hash stringlengths 32 32 | doc_id stringlengths 7 13 | section stringlengths 3 121 | content stringlengths 0 2.2M |
|---|---|---|---|
fd0dfedfef42989b94ca047875b7899e | 101 291 | 2 References | The following documents contain provisions which, through reference in this text, constitute provisions of the present document. • References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific. • For a specific reference, subsequent revisions do not apply. • For a non-specific reference, subsequent revisions do apply. • A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same number. [1] ISO/IEC 13818-1: "Information technology - Generic coding of moving pictures and associated audio information: Systems". [2] EN 300 468: "Digital Video Broadcasting (DVB); Specification for Service Information (SI) in DVB systems". [3] ETR 290: "Digital Video Broadcasting (DVB); Measurement guidelines for DVB systems". [4] EN 300 429: "Digital Video Broadcasting (DVB); Framing structure, channel coding and modulation for cable systems". [5] EN 300 421: "Digital Video Broadcasting (DVB); Framing structure, channel coding and modulation for 11/12 GHz satellite services". [6] EN 300 744: "Digital Video Broadcasting (DVB); Framing structure, channel coding and modulation for digital terrestrial television". [7] ISO/IEC 639-2: "Codes for the representation of names of languages -- Part 2: Alpha-3 code". [8] ISO/IEC 8859-1: "Information processing - 8-bit single-byte coded graphic character sets - Part 1: Latin alphabet No. 1". 7 TR 101 291 V1.1.1 (1998-06) The syntax of the Testdata contained in PID 0x001D is based on the structure of the Private section as defined in ISO/IEC 13818-1 [1]. A testdata table may be made of several testdata sections. Different testdata tables (for different applications) are specified by their table_id and table_id_extension values. One testdata table shall have only one priority level, so only complete tables may be replaced or removed. The values for structure elements "table_id" and "descriptor_tag" may be user defined as specified in ISO/IEC 13818-1 [1]. In the PSI PMT table, the use of a specific descriptor would allow to precise if, for a given elementary stream, there is corresponding test data in the PID 0x1D stream. |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 3 Definitions and abbreviations | |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 3.1 Definitions | For the purposes of the present document, the following definitions apply: MPEG-2: refers to the standard ISO/IEC 13818 [1]. Systems coding is defined in part 1. Video coding is defined in part 2. Audio coding is defined in part 3. multiplex: a stream of all the digital data carrying one or more services within a single physical channel. Service Information (SI): digital data describing the delivery system, content and scheduling/timing of broadcast data streams etc. It includes MPEG-2 PSI together with independently defined extensions. Transport Stream (TS): a TS is a data structure defined in ISO/IEC 13818-1 [1]. It is the basis of the ETSI Digital Video Broadcasting (DVB) standards. |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 3.2 Abbreviations | For the purposes of the present document, the following abbreviations apply: BER Bit Error Rate bslbf bit string, left bit first CRC Cyclic Redundancy Check CW Continuous Wave DVB Digital Video Broadcasting DVB-C Digital Video Broadcasting baseline system for digital cable television (EN 300 429) DVB-S Digital Video Broadcasting baseline system for digital satellite television (EN 300 421) DVB-T Digital Video Broadcasting baseline system for digital terrestrial television (EN 300 744) EB Errored Block ES Errored Second EIT Encoded Information Type ETR ETSI Technical Report ETS European Telecommunication Standard IEC International Electrotechnical Commission IRD Integrated Receiver Decoder ISO International Organisation for Standardisation MMDS Microwave Multi-point Distribution Systems (or Multichannel Multi-point Distribution Systems) MPEG Moving Picture Experts Group MPTS Multiple Presentation Time Stamps MVDS Multi-point Video Distribution Systems NIT Network Information Table NST Network Status Table PCR Program Clock Reference PID Packet Identifier 8 TR 101 291 V1.1.1 (1998-06) PTS Presentation Time Stamps QEF Quasi Error Free r.m.s root mean square RS Reed Solomon SDP Severely Disturbed Period SDT Service Description Table SES Seriously Errored Second SFN Single Frequency Network SPTS Multiple Presentation Time Stamps TDT Target Designation Transmitter TS Transport Stream TV Television UI Unit Interval uimsbf unsigned integer, most significant bit first UTC Universal Time Co-ordinated |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 4 Introduction | |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 4.1 Background | The Digital Video Broadcasting (DVB) set of digital TV standards specify baseline systems for various transmission media: satellite, cable, terrestrial, etc. Each baseline system standard defines the channel coding and modulation schemes for that transmission medium. The source coding adopted was from the MPEG-2 standard. The design of these new systems has created a demand for a common understanding of measurement techniques and the interpretation of measurement results, this led to the introduction of the "DVB Measurement Guidelines" ETR 290 [3]. The deployment of complex digital broadcasting network architectures raised the following requirements: • In order to make the test data independent of any PSI / SI table within a TS and to allow the packets to be freely defined without disturbing any current equipment, a specific PID from the DVB reserved range has been assigned. The number assigned was 0x1D. • Test data may be inserted into an existing TS by replacing null packets with packets containing the test data with the assignment PID 0x1D. Alternatively test data may be introduced via a multiplexer in which case it is at the discretion of the multiplex operator to assign sufficient bandwidth to PID 0x1D. Annex A provides an indication of the likely bandwidth requirements for various applications. |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 4.2 Summary of technical requirements | The chosen solution allows for the following requirements: - technical compatibility with MPEG / DVB standards to ensure that existing equipment will continue to work with transport streams containing PID 0x1D. This will also enable potential reduction of development effort to enable full support of PID 0x1D applications in future equipment implementations; - support for all currently identified application areas; - the provision should be made for user defined solutions to meet the private needs of network operators; - simplification of the test data inserter and test data removal equipment; - prioritization of test data to allow end-to-end communication across a network or the re-use of test data capacity within a network as appropriate to the application. The prioritization of test data packets shall allow their transmission within a network or across network operator borders. 9 TR 101 291 V1.1.1 (1998-06) |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5 Syntax of PID 0x001D applications | All table_ids and descriptor_tags defined in the present document are only valid in the context of packets with PID 0x1D. |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.1 Testdata section | Table 1 defines the structure for testdata sections, transmitted in transport streams with PID 0x001D. Table 1: Testdata section Syntax No. of bits Mnemonic testdata_section() { table_id 6 uimsbf priority_level 2 uimsbf section_syntax_indicator 1 bslbf reserved 3 bslbf testdata_section_length 12 uimsbf if (section_syntax_indicator == 0) { for (i=0; i< test_data_section_length; i++){ testdata_byte 8 uimsbf } } else { user_defined 8 uimsbf table_id_extension 8 uimsbf reserved 2 bslbf version_number 5 uimsbf current_next_indicator 1 bslbf section_number 8 uimsbf last_section_number 8 uimsbf reserved 4 bslbf descriptors_length 12 uimsbf for (i=0;i<descriptors_length;i++){ descriptor() } for (i=0; i< test_data_section_length - descriptors_length -11; i++){ testdata_byte 8 uimsbf } CRC_32 32 rpchof } } 10 TR 101 291 V1.1.1 (1998-06) |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.2 Semantic definition of fields in testdata section | table_id: This is a 6-bit field, the value of which identifies the type of testdata table this section belongs to (see also table 3). NOTE: When using the PID 0x1D, the table_id can be chosen from the whole range except the values reserved by MPEG. If the concept is implemented under another PID, further constraints for the choice of table_id have to be considered. priority_level: This 2-bit field will be used for priority handling as specified in table 2. Table 2: Priority levels and description Priority Level Description 0x00 low_priority, single hop testing, either transport or distribution 0x01 medium_priority, multiple hop testing, either transport or distribution 0x02 high_priority, transport path tests only, no distribution paths 0x03 super_priority, end-to-end testing, including both section_syntax_indicator: When set to 1, it indicates that the testdata section follows the generic section syntax beyond the testdata_section_length field. When set to "0", it indicates that the testdata_bytes immediately follow the testdata_section_length field. reserved: This 3 bits shall all be set to 1. testdata_section_length: A 12-bit field. It specifies the number of remaining bytes in the testdata section immediately following the testdata_section_length field up to the end of the testdata_section. The value in this field shall not exceed 4 093. user_defined: This 8-bit field is user defined and may be used for any purpose. table_id_extension: This 8-bit field is used for the table_id_extension. Use and values are defined as specified in table 3. The values 0x00 and 0xFF are reserved for future use. version_number: This 5-bit field is the version number of the testdata_section. The version_number shall be incremented by 1 modulo 32 when a change in the information carried within the testdata_section occurs. current_next_indicator: A 1-bit field, which shall be set to 1. section_number: This 8-bit field gives the number of the testdata_section. The section_number of the first section in a testdata table shall be 0x00. The section_number shall be incremented by 1 modulo 256 with each additional section in this testdata table. last_section_number: This 8-bit field specifies the number of the last section (that is, the section with the highest section_number) of the testdata table of which this section is a part. reserved: 4 bits which shall be set to "0". descriptors_length: A 12-bit field. It specifies the number of bytes in the descriptors immediately following the descriptors_length field up to the start of Testdata bytes. The value in this field shall not exceed 4 082. The number of descriptors is user definable and can be zero or more. descriptor: See table 4 for list of predefined descriptors. Users may add their own descriptors, where descriptor_tags shall not be used twice. testdata_byte: One or more testdata bytes, to be defined. Informative examples for structures of testdata bytes are given in clause 5 at the end of the present document. 11 TR 101 291 V1.1.1 (1998-06) CRC_32: This is a 32-bit field that contains the CRC value that gives a zero output of the registers in the decoder defined in annex B of ISO/IEC 13818-1 [1] after processing the entire testdata section. |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.3 Definition of subtables | Table 3 gives a summary of possible values for the table_id and table_id_extension fields, used to identify the type of subtable (one or more sections) inside the Test-PID 0x1D. Table 3: Definition of subtables table_id table_id_extension 0x00 to 0x0F reserved not applicable 0x10 measurement_table 0x01 video_measurement 0x02 audio_measurement 0x03 transmission_measurement 0x04 protocol_analysis 0x05 to 0xFE to be defined 0x11 test_signal_table 0x01 PRBS 0x02 to 0xFE to be defined 0x12 remote_control_table 0x01 measurement_system 0x02 to 0xFE to be defined 0x13 reception_status_table not applicable 0x14 network_status_table not applicable 0x15 to 0x3C DVB MG reserved DVB MG reserved 0x3D User defined User defined 0x3E DVB MG reserved DVB MG reserved 0x3F reserved not applicable |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.4 Descriptors | The number of descriptor() is user definable and can be zero or more. |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.4.1 Descriptor coding | Following semantics apply to all the descriptors defined in this subclause. descriptor_tag: The descriptor tag is an 8-bit field which identifies each descriptor. Those values with MPEG-2 normative meaning are described in ISO/IEC 13818-1 [1]. The values of descriptor_tag used for Test-PID 0x1D are given in table 4. 12 TR 101 291 V1.1.1 (1998-06) Table 4: Descriptor identification Descriptor Tag Value elementary_id_descriptor 0x40 content_information_descriptor 0x41 source_identifier_descriptor 0x42 test_signal_descriptor 0x43 time_reference_descriptor 0x44 GPS_descriptor 0x45 reduced_PCR_descriptor 0x46 program_descriptor 0x47 to be defined 0x48 to 0xFE descriptor_length: The descriptor length is an 8-bit field specifying the total number of data bytes of the descriptor immediately following the descriptor_length field. |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.4.2 Elementary id descriptor | Table 5: elementary_id_descriptor Syntax No. of bits Mnemonic elementary_id_descriptor() { descriptor_tag 8 uimsbf descriptor_length 8 uimsbf id_type 3 uimsbf if (id_type <= 3) { elementary_stream_PID 13 uimsbf } else { reserved_for_future_use 13 uimsbf } } 13 TR 101 291 V1.1.1 (1998-06) id_type: A 3-bit field. A value of lower than or equal to 3 indicates that the following datafield contains the PID of an elementary stream, for which measurement values (Video or Audio) are available (see table 5A). Values 0x4 to 0x7 are reserved for future use. Table 5A id_type Value 0x0 user defined 0x1 for video stream 0x2 for audio stream 0x3 for data stream 0x4 to 0x7 reserved for future use elementary_stream_PID: A 13-bit field, which contains the PID of an elementary stream, for which measurement values (Video or Audio) are available. The value 0x1FFF is forbidden (PID of null packets). reserved_for_future_use: A 13-bit field, which shall be set to 0x1FFF. |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.4.3 Content information descriptor | Table 6: content_information_descriptor Syntax No. of bits Mnemonic content_information_descriptor() { descriptor_tag 8 uimsbf descriptor_length 8 uimsbf ISO_639_language_code 24 uimsbf for (i=0; i<N; i++) { text_char 8 uimsbf } } ISO_639_language_code: This 24-bit field contains the ISO/IEC 639-2 [7] three character language code of the language of the following content information. Both ISO 639-2/B or ISO 639-2/T may be used. Each character is coded into 8 bits according to ISO/IEC 8859-1 [8] and inserted into the 24-bit field. EXAMPLE: French has 3 character code "fre", which is coded as "0110 0110 0111 0010 0110 0101" text_char: This is an 8-bit field. The string of character fields is user definable and has to be coded using character sets and methods described in annex A of EN 300 468 [2]. 14 TR 101 291 V1.1.1 (1998-06) |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.4.4 Source identifier descriptor | This descriptor is used for identification of the source of Test data, inserted into Test-PID 0x1D. This identifier gives information concerning the location of insertion, provider and type of Testdata. Table 7: source_identifier_descriptor Syntax No. of bits Mnemonic source_identifier_descriptor() { descriptor_tag 8 uimsbf descriptor_length 8 uimsbf for (i=0; i< descriptor_length / 2; i++) { source_identifier_id 16 uimsbf } } source_identifier_id: This is an 16-bit field. It contains user definable codes for identification of Testdata insertion parameters. As an example, the source_identifier_id may contain codes for the insertion point and/or the provider of inserted Testdata. The values 0x0000 and 0xFFFF are reserved and shall not be used. |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.4.5 Test signal descriptor | This descriptor is used for identification of the type of the inserted testsignal and is intended use. Table 8: test_signal_descriptor Syntax No. of bits Mnemonic test_signal_descriptor() { descriptor_tag 8 uimsbf descriptor_length 8 uimsbf signal_type 1 uimsbf intended_use 2 uimsbf signal_id 13 uimsbf } signal_type: The signal_type is a single bit field to allow freedom in the definition of the test signals. Signal_type "0" is meant for "user defined" signals, while signal_type "1" is intended for standardized signals to be defined by agreement in the present document. 15 TR 101 291 V1.1.1 (1998-06) Table 9: Test signal_id table (for signal_type=0) Value Description 0x0000 reserved 0x0001 to 0x1FFE User defined 0x1FFF reserved Table 10: Test signal_id table (for signal_type=1) Value Description 0x000 reserved 0x001 Time Reference 0x002 PRBS #1 0x003 Pathological 1, Reverse of the energy dispersal for all "ones" 0x004 Pathological 2, Reverse of the energy dispersal for all "zeroes" 0x005 Pathological 3, Reverse of the energy dispersal for 8 pakets of all "ones" followed by 8 packets of all "zeroes". ··· Future use 0x3FF reserved signal_id: The signal_id is a fixed 13 bit field indicating the type of test signal. Up to 8 192 different test signals can be defined in each of the two types of signals. Table 11: Intended use table Value Description 00 Undefined 01 In-service measurements 10 Out-of-service measurements 11 Both intended_use: The intended_use is a two bit field used as an indicator of the appropriate use of the signal. 16 TR 101 291 V1.1.1 (1998-06) |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.4.6 Time reference descriptor | This descriptor can be used as a reference for all test equipment to measure delays in the signal path. Table 12: time_reference_descriptor Syntax No. of bits Mnemonic time_reference_descriptor() { descriptor_tag 8 uimsbf descriptor_length 8 uimsbf reference_type 6 uimsbf precision_range 2 uimsbf UTC_time 40 uimsbf if (precision_range ==1) { reserved 6 uimsbf millisecond_extension 10 uimsbf } if (precision_range ==2) { reserved 4 uimsbf millisecond_extension 10 uimsbf microsecond_extension 10 uimsbf } if (precision_range ==3) { reserved 2 uimsbf millisecond_extension 10 uimsbf microsecond_extension 10 uimsbf nanosecond_extension 10 uimsbf } reference_type: This 6-bit field indicates the nature of the reference clock, so the receiver can contrast what is the best fit for the measurement. The use of a XCO (value 0), could not provide a good enough absolute time reference, however still can be an option of the test generator for measurements of delay in close loop systems, such as a terrestrial transmitter and a terrestrial reference receiver measured by a test generator-analyzer equipment used for transmitter delay measurements. 17 TR 101 291 V1.1.1 (1998-06) Table 13: Reference_type table Value Description 0 Internal XCO of the test generator 1 GPS grade 1 2 GPS grade 2 3 Timing Reference Radio Station 4 Future use 5 Future use 6 1x10-6 7 1x10-7 8 1x10-8 9 1x10-9 10 1x10-10 11 1x10-11 12 1x10-12 ... Future use 63 Future use precision_range: A 2-bit field indicating the precision of the time reference used. UTC_time: This 40-bit field contains the current time and date in UTC and MJD (see annex C of EN 300 468 [2]). This field is coded as 16 bits giving the 16 LSBs of MJD followed by 24 bits coded as 6 digits in 4-bit BCD. millisecond_extension: This 10-bit field should contain a binary number indicating the number of milliseconds. microsecond_extension: This 10-bit field should contain a binary number indicating the number of microseconds. nanosecond_extension: This 10-bit field should contain a binary number indicating the number of nanoseconds. NOTE: In GPS applications, the 10 MHz reference signal can be used for the generation of the time extension. The resolution of the extension should be given up to the nanosecond, however the increment can be made to tens of nanosecond or hundreds of nanosecond, depending on the reference accuracy. 18 TR 101 291 V1.1.1 (1998-06) |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.4.7 GPS_descriptor | Table 14: GPS_descriptor Syntax No. of bits Mnemonic GPS_descriptor() { descriptor_tag 8 uimsbf descriptor_length 8 uimsbf north_south 1 uimsbf geo_latitude 23 uimsbf east_west 1 geo_longitude 23 uimsbf geo_elevation 16 uimsbf } NOTE: This table may have to be reviewed. |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.4.8 "reduced PCR" descriptor | When the "reduced PCR" descriptor is inserted in a table which contains a "time_reference_descriptor", the following assumption is made. The "reduced PCR" field conveys the 32 most significant bits of the PCR_base, referring to the TS packet arriving at the instant at which the time_reference field is derived from the timing reference. Table 15: reduced_PCR descriptor Syntax No. of bits Mnemonic reduced_PCR_descriptor() { descriptor_tag 8 uimsbf descriptor_length 8 uimsbf reduced_PCR_base 32 uimsbf } 19 TR 101 291 V1.1.1 (1998-06) |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.4.9 program_descriptor | The program number and the PID number of the PMT can be indicated before "elementary_id_descriptor". Thus, the application can find easily complementary information in PSI/SI if needed. Table 16: program_descriptor Syntax No. of bits Mnemonic program_descriptor() { descriptor_tag 8 uimsbf descriptor_length 8 uimsbf program_number 16 uimsbf reserved 3 uimsbf program_map_pid 13 uimsbf } |
fd0dfedfef42989b94ca047875b7899e | 101 291 | 5.5 Usage of adaptation fields within packets with PID 0x1D | Many applications using the packets with PID 0x1D will use no adaptation_field, payload only (adaptation_field_control = "01"). Some applications however will use adaptation_field only, no payload (adaptation_field_control = "10"). In this case, the first 4 bytes of the adaptation field should follow the syntax of the Transport Stream adaptation field (table 2-7 of ISO/IEC 13818-1 [1]) but with all indicators and flags set to "zero" with the exception of the transport_private_data_flag which shall be set to "one". The first private_data_byte of the adaptation field of each packet shall be an exact copy of the table_id (6 bits) followed by the priority level (2 bits) as defined above in table 1 (test data section). The remaining 180 bytes, from section_syntax_indicator to CRC32, constitute the data bytes for all the table_id defined in table 3 with the exception of table_id = 0x3E which may be defined by DVB MG for future use. By using this adaptation field, the type of application, as well as the priority level will be present in each test packet and will allow for individual processing of each packet reducing delays and memory buffers. When adaptation_field_control = "10", Packet Unit Start Indicator shall be "1" if the transport packet carries the beginning of a test_data_section which can be distinguished by the following sequence: byte "table_id / priority_level", followed by 2 bytes "section_syntax_indicator / reserved / test_data_section_length". 20 TR 101 291 V1.1.1 (1998-06) Annex A (informative): Detailed description of table content (testdata_byte) A.1 Network Status Table (NST) A.1.1 Introduction In a digital broadcast environment with a multitude of services there is a need for highly automated means to monitor and subsequently to provide information (e.g. failure messages) about the availability of equipment and services as well as of service components such as video, audio and subtitling and of Service Information (SI) tables. In order to support the detection of service and equipment failures, to provide information for remedial measures and to efficiently log such events, a transport mechanism, the Network Status Table (NST) has been defined. This system will serve for conveying diagnostic information about the consistency of all DVB/MPEG-2 multiplexes within a network. A.1.2 Functionality NSTs can be generated at any point in the transmission chain to signal missing streams (e.g. video, audio, subtitle or accompanied data) or Service Information components (e.g. NIT, SDT, EIT or TDT) within a multiplex. As the underlying concept of the NST system is to detect and signal failures at the point where they are generated, the system supervisor of the DVB/MPEG-2 encoding, multiplexing and modulation equipment should monitor the correct functioning of all equipment modules and should generate an NST in the case a service failure occurs for longer than 10 seconds. NSTs shall then be periodically transmitted every 10 seconds until the failure is fixed. In addition to faulty equipment modules also missing input streams can be identified by subsequent modules in the transmission chain which then generate corresponding NSTs. A.1.3 Syntax of the Network Status Table (NST) The syntax of the NST is conforming to the one defined in the standard ISO/IEC 13818-1 [1] for the definition of private sections. The Network Status Table shall be carried on PID 0x001D using the normal payload_unit_start_indicator/pointer field mechanism described in the standard ISO/IEC 13818-1 [1]. A NST shall be inserted in maximum one Transport Stream packet resulting in a maximum table size of 183 bytes. 21 TR 101 291 V1.1.1 (1998-06) Structure element No. of bits Mnemonics network_status_section(){ table_id 8 uimsbf section_syntax_indicator 1 bslbf DVB_reserved 1 bslbf ISO_reserved 2 bslbf section_length 12 uimsbf transport_stream_id 16 uimsbf original_network_id 16 uimsbf NST_version_number 4 uimsbf Fault_source 12 uimsbf Fault_type 16 uimsbf for (i=0;i<N;i++){ Fault_major 16 uimsbf Fault_minor 16 uimsbf } } Table_id = 0x14 Section_syntax_indicator = 0 DVB_reserved = 1 Section_length: This is a 12-bit field, the first two bits of which shall be "00". It specifies the number of bytes of the section, starting immediately following the section_length field. The section_length shall not exceed 180 bytes so that the entire section has a maximum length of 183 bytes. Transport_stream_id: This is a 16-bit field which serves as a label to identify the TS where the error or warning has occurred. If the TS is undefined the Transport_stream_id shall be 0x0000. Original_network_id: This 16-bit field gives the label identifying the network_id of the originating delivery system of the TS where the error or warning has occurred. If the network is undefined the Original_network_id shall be 0x0000. NST_version_number: This 4-bit field identifies the version number of the NST structure. Currently, the NST_version_number shall be set to "0". Fault_source: This is a code that, together with the transport_stream_id and the original_network_id, identifies the origin of the failure. Fault_source values can be defined by the operator of the TS within the ranges defined in table A.2. Fault_type: This 16-bit field identifies the basic type of errors or warnings. Only values described in table A.3 are defined. In every NST section only one Fault_type shall be listed resulting in only one basic type of error or warning per NST. NOTE: Table A.3 contains all TS errors as defined in ETR 290 [3]. 22 TR 101 291 V1.1.1 (1998-06) Fault_major: This 16-bit field provides more detailed information about the errors or warnings as defined by the Fault_type. Depending on the value of the Fault_type, the Fault_major has different meanings. The Fault_types for which Fault_major are defined is given in table A.1. If for a Fault_type no Fault_major code is defined, the loop within the NST shall be empty. Fault_minor: This field provides additional information about the error or warning as described by the combination of Fault_type and Fault_major. If no Fault_minor code is defined for a Fault_major code, the Fault_minor field shall be present and all bits shall be set to "1". Table A.1: Fault_major and Fault_minor for different Fault_types Fault_type = 0x0003: In case of SI_repetition_errors fault_major shall contain the corresponding table_id. Fault_minor shall be 0xFF. Fault_type = 0x0004: In case of EIT_errors Fault_major is defined in table A.6. Fault_minor contains the service_id of the service for which the EIT_error has occurred. Fault_type = 0x0006: In case of Unreferenced_PID fault_major shall contain the unreferenced PIDs. The fault_minor shall be 0xFF. Fault_type = 0x000E: In case of Continuity_count_error fault_major shall contain the PID of the packets, where the discontinuity has occurred. Fault_minor shall be 0xFF. Fault_type = 0x0010: In case of PID_error fault_major shall contain the missing PID. Fault_minor shall be 0xFF. Fault_type = 0x0012: In case of CRC_errors fault_major shall contain the table_ids of the table in error. Fault_minor shall be to 0xFF Fault_type = 0x0013: In case of PCR_accuracy_error fault_major shall contain the corresponding PID. Fault_minor shall be 0xFF. Fault_type = 0x0015: In case of PTS_error fault_major field shall contain the corresponding PID. Fault_minor shall be 0xFF. Fault_type = 0x0100: In case of missing components of a service Fault_major is equal to the service_id of this service. Fault_minor is defined in table A.4. Fault_type = 0x0104, 0x0105, 0x0106: If the BER is above a user definded threshold Fault_major defines the measured BER value according to table 23. Fault_type = 0x110 If the content of a section is changed without changing its version_number, fault_major shall contain the table_ids of the of the tables in error. Fault_minor shall be 0xFF. NOTE 1: If fault_major contains a table_id, it shall be placed in the second byte of fault_major. The first 8 bits of fault_major shall be set to "0x0". NOTE 2: If fault_major contains a PID, it shall be placed in the last 13 bits of fault_major. The first 3 bits of fault_major shall be set to "000". 23 TR 101 291 V1.1.1 (1998-06) Table A.2: Fault_source Fault_source range Description 0x0000 Undefined 0x0001,...,0x0064 SI-editing & controller 0x0065,...,0x01F4 Audio encoder 0x01F5,...,0x0226 Video encoder 0x0227,...,0x03B6 Data inserter 0x03B7,...,0x03E8 CA system 0x03E9,...,0x041A Multiplexer 0x041B,...,0x044C Re-multiplexer 0x044D,...,0x047E Modulator 0x047F,...,0x060E Decoder 0x060F,....0x0640 Network termination 0x0641,...,0x09FB DVB reserved 0x09FC,...,0x0FFF User defined 24 TR 101 291 V1.1.1 (1998-06) Table A.3: Fault_type Fault_type Description 0x0000 Undefined 0x0001 NIT_error (No. 3.1) 0x0002 SDT_error (No. 3.5) 0x0003 SI_repetition_error (No. 3.2) 0x0004 EIT_error (No. 3.6) 0x0005 Buffer_error (No. 3.3) 0x0006 Unreferenced_PID (No. 3.4) 0x0007 Empty_buffer_error (No. 3.9) 0x0008 TDT_error (No. 3.8) 0x0009 PAT_error (No. 1.3) 0x000A CAT_error (No. 2.6) 0x000B Data_delay_error (No. 3.10) 0x000C TS_sync_loss (No. 1.1) 0x000D Sync_byte_error (No. 1.2) 0x000E Continuity_count_error (No. 1.4) 0x000F PMT_error (No. 1.5) 0x0010 PID_error (No. 1.6) 0x0011 Transport_error (No. 2.1) 0x0012 CRC_error (No. 2.2) 0x0013 PCR_error (No. 2.3) 0x0014 PCR_accuracy_error (No. 2.4) 0x0015 PTS_error (No. 2.5) 0x0016 RST_error (No. 3.7) 0x0020 TSDT_error (for DSNG) 0x0060 Input signal missing 0x0080 Transport Stream missing 0x0100 Component of service missing 0x0104 BER before Viterbi above threshold 0x0105 BER before RS above threshold 0x0106 BER after RS above threshold 0x0110 PSI/SI section modified without changing the version_number Other fault_type <= 0x0800 DVB reserved Fault_type > 0x0800 User defined NOTE: The numbers in bracket specify the corresponding TS error as defined in ETR 290 [3]. 25 TR 101 291 V1.1.1 (1998-06) Table A.4: Fault_minor codes for Fault_type = 0x0100 (Component missing) Fault_major specifies the service_id of the service with missing components. Fault_minor if Fault_type = 0x0100 Description 0x0001 Video component missing 0x0002 Audio component missing 0x0004 EBU Teletext subtitles missing 0x0008 Associated EBU Teletext missing 0x0010 Data component missing 0x0011 ECM missing 0x0012 EMM missing 0x0020 DVB subtitling missing 0x0040 PMT missing Other values DVB reserved Table A.5: Fault_major codes for Fault_type = 0x0002 (SDT_error) Fault_major if Fault_type =0x0002 (SDT error) Description 0x0001 SDT (actual TS) error 0x0002 SDT (other TS) error Other values DVB reserved Table A.6: Fault_major codes for Fault_type = 0x0004 (EIT_error) Fault_major If Fault_type = 0x0004 (EIT error) Description 0x0001 EIT (actual TS, p/f) error 0x0002 EIT (actual TS, schedule) error 0x0003 EIT (other TS, p/f) error 0x0004 EIT (other TS, schedule) error Other values DVB reserved 26 TR 101 291 V1.1.1 (1998-06) Table A.7: Fault_major codes for Fault_type = 0x0104, 0x105, 0x0106 (BER Measurement) Fault_major if Fault_type = 0x0104, 0x0105, 0x0106 (BER Measurement) Description 0x0000 BER > 10E-2 0x0001 10E-2 > BER > 10E-3 0x0002 10E-3 > BER > 10E-4 0x0003 10E-4 > BER > 10E-5 0x0004 10E-5 > BER > 10E-6 0x0005 10E-6 > BER > 10E-7 0x0006 10E-7 > BER > 10E-8 0x0007 10E-8 > BER > 10E-9 0x0008 10E-9 > BER > 10E-10 0x0009 10E-10 > BER > 10E-11 0x000A 10E-11 > BER > 10E-12 Other values DVB reserved 27 TR 101 291 V1.1.1 (1998-06) Annex B (informative): Examples of use for the test packets This annex contains informative examples of testdata structures. B.1 Example of Testdata structure for a measurement table Table B.1 gives an informative example of a Testdata structure including video measurement values. Table B.1: Example of Testdata Structure Structure element No. of bits Value testdata_section() { table_id 6 0x10 priority_level 2 0x0 section_syntax_indicator 1 0x1 reserved 3 0x7 testdata_section_length 12 0x04C user_defined 8 0x01 table_id_extension 8 0x01 reserved 2 0x3 version_number 5 0x00 current_next_indicator 1 0x1 section_number 8 0x00 last_section_number 8 0x00 reserved 4 0x00 descriptors_length 12 0x025 elementary_id_descriptor { descriptor_tag 8 0x40 descriptor_length 8 0x02 id_type 3 0x0 elementary_stream_pid 13 0x0100 (Video PID) } content_information_descriptor { 28 TR 101 291 V1.1.1 (1998-06) Structure Element No. of bits Value descriptor_tag 8 0x42 descriptor_length 8 0x1B ISO_639_language_code 24 "fre" text_char { } 8 "mesures de qualité vidéo" } source_identifier_descriptor() { descriptor_tag 8 0x42 descriptor_length 8 0x02 for (i=0; i< descriptor_length / 2; i++) { source_identifier_id 16 0x0001 } } testdata_bytes { reduced_measurement_time_stamp 8 0x4A sequence_length 8 0x03 number_of_measured_frames 8 0x02 (NOMF) number_of_video_parameters 8 0x03 (NOVP) for (i=0;i< NOMF;i++){ for (k=0; k< NOVP; k++) { video_parameter(k) 32 Meas. Value in Float Format } } } CRC_32 32 calculated for the whole section } 29 TR 101 291 V1.1.1 (1998-06) B.2 Example of Testdata structure for a Testsignal table Generation of the PRBS test sequence Figure B.1: PRBS test sequence generator It is recommended to use the PRBS 223 -1 with a length of 8 388 607 bits. The input test sequence can be generated by a shift register of length 23 with suitable feedbacks. The generator polynomial shall be 1+x18+x23. The initialisation word in the PRBS generator is "all ones". The PRBS data should be inserted in the testdata_bytes. The PRBS generator is reset at the beginning of the first section related to the transmission of the PRBS. Table B.2 gives an informative example of a Testdata structure including a PRBS test sequence. 30 TR 101 291 V1.1.1 (1998-06) Table B.2: Example of Testsignal insertion Structure Element No. of bits Value testdata_section() { table_id 6 0x11 priority_level 2 0x0 section_syntax_indicator 1 0x1 reserved 3 0x7 testdata_section_length 12 0x83D user_defined 8 0x01 table_id_extension 8 0x01 reserved 2 0x3 version_number 5 0x00 current_next_indicator 1 0x1 section_number 8 0x00 last_section_number 8 0x00 reserved 4 0x00 descriptors_length 12 0x031 content_information_descriptor { descriptor_tag 8 0x41 descriptor_length 8 0x19 ISO_639_language_code 24 "eng" text_char { } 8 "PRBS Testsequence No.1" } source_identifier_descriptor() { descriptor_tag 8 0x42 descriptor_length 8 0x04 source_identifier_id (i=0) 16 0x0001 (Used as Uplink ID) source_identifier_id (i=1) 16 0x1234 (Used as Source ID) } time_reference_descriptor { descriptor_tag 8 0x44 descriptor_length 8 0x0B reference_type 6 0x00 (Internal XCO) precision_range 2 0x00 (No extension) UTC_time 40 0xC079124501 } test_signal_descriptor { descriptor_tag 8 0x43 descriptor_length 8 0x02 signal_type 1 0x1 (Predefined) intended_use 2 0x2 (Out of service) signal_id 13 0x0002 (PRBS#1) } testdata_bytes { for (i=0;i<2048;i++) { PRBS_data 8 0x00 } CRC_32 32 calculated for the whole section } 31 TR 101 291 V1.1.1 (1998-06) B.3 Example of Testdata structure for a Network Status Table (NST) Table B.3 gives an informative example of a Testdata structure, including a Network Status Table for transmission of information (e.g. failure messages) about the availability of services as well as of service components such as video, audio and subtitling and of Service Information (SI) tables. Table B.3: Example of Network Management Table Structure Element No. of bits Value testdata_section() { table_id 6 0x14 priority_level 2 0x0 section_syntax_indicator 1 0x0 reserved 3 0x7 testdata_section_length 12 0x00C testdata_bytes { transport_stream_id 16 0x0001 original_network_id 16 0x0002 NST_version_number 4 0x0 fault_source 12 0x03E9 (Multiplexer) fault_type 16 0x0100 (Component of service missing) fault_major 16 0x0300 (Service ID of missing service) fault_minor 16 0x0002 (Audio component missing) } } B.4 Example of Testdata structure for a Reception Status Table (RST) Table B.4 gives an informative example of a Test data structure including telemetry data tables generated by a satellite on-board multiplexer. This type of multiplexer takes TSs as inputs and outputs a single TS or several TSs containing multiple programmes. The input TSs come from different DVB-S demodulators. Table B.4 gives information about the quality of the DVB-S signals received by the satellite, such as carrier level, frequency drift, lock status, decoding capacity overflow, etc. This information is formatted into blocks and passed into an auxiliary input of the multiplexer. The multiplexer inserts the telemetry data into the output TS two times per second. 32 TR 101 291 V1.1.1 (1998-06) Table B.4: Example of Multiplex Diagnostic Table Structure element No. of bits Value testdata_section() { table_id 6 0x13 priority_level 2 0x0 section_syntax_indicator 1 0x0 reserved 3 0x7 testdata_section_length 12 N × 8 testdata_bytes { N × 64 N blocks of 4 words of 16 bits } B.5 Example of test data structure for a Remote Control Table (RCT) The need for remote control application is appearing in the terrestrial broadcasting environment. It consists in controlling, from the emission site, the equipment in charge of switching from national programs to local programs, or to advertising programs. Figure B.2 illustrates an example of a transmission chain. 33 TR 101 291 V1.1.1 (1998-06) Satellite Modulator Single Program Encoder Remultiplexer Satellite Demodulator Switching unit driven by remote control tables from PID 0x1D demultiplexing Other single program endoders MPTS MPTS National Program TV1 Single Program Encoder Local Program TV1 SPTS MPTS Terrestrial Modulator SPTS PID 0x1D for Remote control bl E R Radio Station timing reference Radio Station timing reference Figure B.2 Information to be transmitted in tables: - one information to announce an imminent switching, for example, some minutes earlier; - one information to validate switching from national to local; - one information to validate switching from local to national; - the instant of switching. - a time reference used by the switching equipment to measure the transmission delay of the received video component from emission point E to reception point R. The knowledge of this delay is needed to maintain switching accuracy; - a PCR reference. The measurement of the delay shall take into account that timing jitter is inevitably created by mux and remux equipment, Moreover, the PID 0x1D timing jitter is not all correlated with the elementary stream because the paths are different on elementary streams and tables. To solve this problem, it is proposed to link the time reference information with the video PCR (see the "reduced PCR" descriptor described in 5.4.8). 34 TR 101 291 V1.1.1 (1998-06) The time_reference descriptor and the reduced PCR descriptor are sent together, for example, some minutes before switching. In this example, the switching equipment shall know the exact type of the elementary stream (audio, video, data -> see stream_type in PMT) for adjusting the switching criteria. Of course, the program number can be known by others means, but direct indication is a more simple and rapid way. Moreover, this is a convenient link with other signalisation. - Program number and the PID number of the PMT are conveyed in the program_descriptor (see 5.4.9). - The "time reference descriptor" is used for coding the instant of switching. The precision shall be about the millisecond to be able to switch at a better accuracy than a picture duration (40 ms). The type of the timing reference is a radio station. Example: On 93/10/13 at 12 h 45 mn 01 sec. 234 millisec. Switching program number 5000 (0x1388) from national to local for the video (PID = 0x100) and the audio (PID=0x101) components. The PID of the PMT is 0x900. table_id = 0x12 for remote_control_table userdefined 8 lower bits are user defined: 0x01 = announcement of imminent switching 0x02 = switching to local 0x03 = switching to national table_id_extension = 0x02 for switching_system 35 TR 101 291 V1.1.1 (1998-06) Table B.5: Example of Remote Control Table Structure element No. of bits Value remote_section() { table_id 6 0x12 priority_level 2 0x0 section_syntax_indicator 1 0x1 reserved 3 0x7 testdata_section_length 12 0xXXX (tbd) userdefined 8 0x02 table_id_extension 8 0x02 reserved 2 0x3 version_number 5 0x00 current_next_indicator 1 0x1 section_number 8 0x00 last_section_number 8 0x00 reserved 4 0x00 remote_descriptors_length 12 0x18 time_date_descriptor() { descriptor_tag 8 0x45 descriptor_length 8 0x08 reference_type 6 0x03 precision_range 2 0x01 UTC_time 40 0xC079124501 reserved 6 millisecond_extension 10 0x234 } program_descriptor { descriptor_tag 8 0x46 descriptor_length 8 0x03 program_number 16 0x1388 reserved 3 program_map_pid 13 0x0900 } elementary_id_descriptor { descriptor_tag 8 0x40 descriptor_length 8 0x02 id_type 3 0x1 elementary_stream_pid 13 0x0100 (Video PID) } elementary_id_descriptor { descriptor_tag 8 0x40 descriptor_length 8 0x02 id_type 3 0x2 elementary_stream_pid 13 0x0101 (Audio PID) } testdata_bytes { } CRC_32 32 calculated for the whole section 36 TR 101 291 V1.1.1 (1998-06) Annex C (informative): Examples for data rates In this annex C several examples are given for estimates of the data rate which needs to be reserved for certain applications of the PID 0x1D. Error messages signalling: Approx. 200 bit/s to 2 kbit/s. This estimate is based on the assumption that the error messages are normally contained in one TS packet and that such a packet is inserted periodically once every ten seconds up to once per second. Test signals distribution (e.g. PRBS): 223-1: 8 Mbyte, over 30 seconds approx. 270 kbit/s. Off-line measurements: Short time 100 % of transmission capacity. Distribution of GPS information: Around 60 kbit/s. Distribution of measurement values: 20 to 40 kbit/s for 1 video and 1 audio stream quality analysis, for other parameters depending on repetition rate 1 to 10 kbit/s. Control of remote equipment: Around 1 kbit/s. Summary: For the above listed applications the range of 200 bit/s to > 270 kbit/s is sufficient while the upper limit may only be required for comparably short periods of time. 37 TR 101 291 V1.1.1 (1998-06) History Document history June 1998 V1.1.1 Publication ISBN 2-7437-2338-6 Dépôt légal : Juin 1998 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 1 Scope | The present document provides guidelines for measurement in Digital Video Broadcasting (DVB) satellite, cable and terrestrial and related digital television systems. The present document defines a number of measurement techniques, such that the results obtained are comparable when the measurement is carried out in compliance with the appropriate definition. The present document uses terminology used in ETSI EN 300 421 [i.5], ETSI EN 300 429 [i.6], ETSI EN 300 468 [i.7] and ETSI EN 300 744 [i.9] and it should be read in conjunctions with them. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 2 References | |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 2.1 Normative references | Normative references are not applicable in the present document. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 2.2 Informative references | References are either specific (identified by date of publication and/or edition number or version number) or non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the referenced document (including any amendments) applies. NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee their long term validity. The following referenced documents are not necessary for the application of the present document but they assist the user with regard to a particular subject area. [i.1] ISO/IEC 13818-1 (ITU-T Recommendation H.222.0): "Information technology - Generic coding of moving pictures and associated audio information: Systems". [i.2] ISO/IEC 13818-4: "Information technology - Generic coding of moving pictures and associated audio information - Part 4: Conformance testing". [i.3] ISO/IEC 13818-9: "Information technology - Generic coding of moving pictures and associated audio information - Part 9: Extension for real time interface for systems decoders". [i.4] Void. [i.5] ETSI EN 300 421: "Digital Video Broadcasting (DVB); Framing structure, channel coding and modulation for 11/12 GHz satellite services". [i.6] ETSI EN 300 429: "Digital Video Broadcasting (DVB); Framing structure, channel coding and modulation for cable systems". [i.7] ETSI EN 300 468: "Digital Video Broadcasting (DVB); Specification for Service Information (SI) in DVB systems". [i.8] ETSI TR 101 211: "Digital Video Broadcasting (DVB); Guidelines on implementation and usage of Service Information (SI)". [i.9] ETSI EN 300 744: "Digital Video Broadcasting (DVB); Framing structure, channel coding and modulation for digital terrestrial television". [i.10] EN 50083-9: "Cable networks for television signals, sound signals and interactive services - Part 9: Interfaces for CATV/SMATV headends and similar professional equipment for DVB/MPEG-2 transport streams", produced by CENELEC. [i.11] Void. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 13 [i.12] Recommendation ITU-T O.151: "Error performance measuring equipment operating at the primary rate and above". [i.13] ETSI EN 300 473: "Digital Video Broadcasting (DVB); Satellite Master Antenna Television (SMATV) distribution systems". [i.14] ETSI TS 101 191: "Digital Video Broadcasting (DVB); DVB mega-frame for Single Frequency Network (SFN) synchronization". [i.15] ETSI EN 300 748: "Digital Video Broadcasting (DVB); Multipoint Video Distribution Systems (MVDS) at 10 GHz and above". [i.16] ETSI EN 300 749: "Digital Video Broadcasting (DVB); Microwave Multipoint Distribution Systems (MMDS) below 10 GHz". [i.17] ISO 639: "Code for the representation of names of languages". [i.18] ETSI EN 301 210: "Digital Video Broadcasting (DVB); Framing structure, channel coding and modulation for Digital Satellite News Gathering (DSNG) and other contribution applications by satellite". [i.19] ETSI ETS 300 813: "Digital Video Broadcasting (DVB); DVB interfaces to Plesiochronous Digital Hierarchy (PDH) networks". [i.20] ETSI ETS 300 814: "Digital Video Broadcasting (DVB); DVB interfaces to Synchronous Digital Hierarchy (SDH) networks". [i.21] Void. [i.22] Void. [i.23] EN 50221: "Common interface specification for conditional access and other digital video broadcasting decoder applications", produced by CENELEC. [i.24] ETSI TS 102 773 (V1.3.1), January 2012: "Digital Video Broadcasting (DVB); Modulator Interface (T2-MI) for a second generation digital terrestrial television broadcasting system (DVB-T2)". [i.25] ETSI TS 102 034 (August 2009): "Digital Video Broadcasting (DVB); Transport of MPEG-2 TS Based DVB Services over IP Based Networks". [i.26] SMPTE 2022-1 (May 2007): "Forward Error Correction for Real-Time Video/Audio Transport Over IP Networks". [i.27] ETSI EN 302 755 (V1.3.1) (April 2012): "Digital Video Broadcasting (DVB); Frame structure channel coding and modulation for a second generation digital terrestrial television broadcasting system (DVB-T2)". [i.28] ETSI EN 302 769 (V1.2.1) (April 2011): "Digital Video Broadcasting (DVB); Frame structure channel coding and modulation for a second generation digital transmission system for cable systems (DVB-C2)". [i.29] ETSI TS 102 991 (V1.2.1) (June 2011): "Digital Video Broadcasting (DVB); Implementation Guidelines for a second generation digital cable transmission system (DVB-C2)". [i.30] ETSI TS 101 154: "Digital Video Broadcasting (DVB); Specification for the use of Video and Audio Coding in Broadcast and Broadband Applications". [i.31] ISO/IEC 13818-2: "Information technology - Generic coding of moving pictures and associated audio information - Part 2: Video". [i.32] ISO/IEC 13818-3: "Information technology - Generic coding of moving pictures and associated audio information - Part 3: Audio". [i.33] ETSI EN 301 192: "Digital Video Broadcasting (DVB); DVB specification for data broadcasting". ETSI ETSI TR 101 290 V1.4.1 (2020-06) 14 [i.34] IETF RFC 791: "Internet Protocol". [i.35] IETF RFC 768: "User Datagram Protocol". [i.36] IETF RFC 3171: "IANA Guidelines for IPv4 Multicast Address Assignments". [i.37] IETF RFC 4445: "A Proposed Media Delivery Index (MDI)". [i.38] Proakis John G.: "Digital Communication", McGraw Hill, 1989. [i.39] Begin G., Haccoun D. and Chantal P.: "High-Rate Punctured Convolutional Codes for Viterbi and Sequential Decoding", IEEE Trans. Commun, vol 37, pp. 1113-1125, November 1989. [i.40] Begin G., Haccoun D. and Chantal P.: "Further Results on High-Rate Punctured Convolutional Codes for Viterbi and Sequential Decoding", IEEE Trans. Commun., vol 38, pp. 1922-1928, November 1990. [i.41] Odenwalder J.P.: "Error Control Coding Handbook", Final report prepared for United States Airforce under Contract No. F44620-76-C-0056, 1976. [i.42] Pratt, Timothy and Bostian Charles W.: "Satellite Communications", John Wiley & Sons, 1986. [i.43] SMPTE 2022-2:2007: "Unidirectional Transport of Constant Bit Rate MPEG-2 Transport Streams on IP Networks". [i.44] COST 207: "Digital land mobile radio communications". NOTE: Available at https://op.europa.eu/en/publication-detail/-/publication/61fc77e7-bca2-4229-8eb4- 77741f0d2ab2. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 3 Definition of terms, symbols and abbreviations | |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 3.1 Terms | For the purposes of the present document, the following terms apply: MPEG-2: Refers to the ISO/IEC 13818, Systems coding is defined in ISO/IEC 13818-1 [i.1], video coding is defined in ISO/IEC 13818-2 [i.31] and audio coding is defined in ISO/IEC 13818-3 [i.32]. multiplex: stream of all the digital data carrying one or more services within a single physical channel Service Information (SI): digital data describing the delivery system, content and scheduling/timing of broadcast data streams, etc. NOTE: Includes MPEG-2 Program Specific Information (PSI) as defined in ISO/IEC 13818-1 [i.1] together with independently defined extensions. Transport Stream (TS): data structure used in many of the Digital Video Broadcasting (DVB) related standards NOTE: Defined in ISO/IEC 13818-1 [i.1]. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 3.2 Symbols | For the purposes of the present document, the following symbols apply: BWSYS System noise power bandwidth FH Frequency (high) FL Frequency (low) KMAX Maximum Carrier Number MIPN N-th Mega-frame Initialization Packet ETSI ETSI TR 101 290 V1.4.1 (2020-06) 15 PB (Variable name of) Bit Error Probability (BEP) PBLOCK (Variable name of) the probability of an undetected error for a block of N symbols PI Number of interleaving T2 frames PN Variable for MIP pointer value PS Symbol Error Probability printf symbol in the C programming language PSIN Error probability of the incoming symbols QS Symbol error probability RI Information rate RT Transmission rate STSM Value of M-th Synchronization Time Stamp TU Symbol duration |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 3.3 Abbreviations | For the purposes of the present document, the following abbreviations apply: ACE Active Constellation Extension ACLR Adjacent Channel Leakage Ratio AFC Automatic Frequency Control AI Amplitude Imbalance ASCII American Standard Code for Information Interchange ASI Asynchronous Serial Interface ATM Asynchronous Transfer Mode AWGN Additive White Gaussian Noise BAT Bouquet Association Table BB Baseband BBFER Baseband Frame Error Rate BCH Bose - Chaudhuri - Hocquenghem code BEP Bit Error Probability BER Bit Error Rate bslbf bit string, left bit first BW BandWidth C/N ratio of RF or IF signal power to noise power CA Conditional Access CAT Conditional Access Table CATV Community Antenna TeleVision CBR Constant Bit Rate CCDF Cumulative Complementary Distribution Function CCI Co-channel Interference CF Correction Factor CFC Number of Frame Closing symbols CI Common Interface COFDM Coded Orthogonal Frequency Division Multiplex CPE Common Phase Error CRC Cyclic Redundancy Check CS Carrier Suppression CSO Composite Second Order CTB Composite Triple Beat CW Continuous Wave DC Direct Current DF Delay Factor DSNG Digital Satellite News Gathering DTG Digital TV Group DVB Digital Video Broadcasting DVB-C Digital Video Broadcasting baseline system for digital cable television NOTE: See ETSI EN 300 429 [i.6]. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 16 DVB-CS Digital Video Broadcasting baseline system for SMATV distribution systems NOTE: See ETSI EN 300 473 [i.13]. DVB-MC Digital Video Broadcasting baseline system for Multi-point Video Distribution Systems below 10 GHz NOTE: See ETSI EN 300 749 [i.16]. DVB-MG DVB Measurement Group DVB-MS Digital Video Broadcasting baseline system for Multi-point Video Distribution Systems at 10 GHz and above NOTE: See ETSI EN 300 748 [i.15]. DVB-S Digital Video Broadcasting baseline system for digital satellite television NOTE: See ETSI EN 300 421 [i.5]. DVB-T Digital Video Broadcasting baseline system for digital terrestrial television NOTE: See ETSI EN 300 744 [i.9]. DVB-X2 2nd generation DVB systems EB Errored Block EIT Event Information Table EIT-F Event Information Table - Future EIT-P Event Information Table - Present EMM Entitlement Management Message ENB Equivalent Noise Bandwidth END Equivalent Noise Degradation ENF Equivalent Noise Floor ES Errored Second ESR Errored Second Ratio ETI Errored Time Interval ETIR Errored Time Interval Ratio ETR ETSI Technical Report ETS European Telecommunication Standard EVM Error Vector Magnitude EVMV Error Vector Magnitude - Voltage FEC Forward Error Correction FEF Future Extension Frames FFT Fast Fourier Transform GI Guard Interval GOP Group of Pictures GPS Global Positioning System GSE Generic Stream Encapsulation GSM Global System for Mobile communications HEX Hexadecimal HP High Priority IBS In-band signalling ICI Inter-Carrier Interference IEC International Electrotechnical Commission IERS International Earth Rotation Service IF Intermediate Frequency IFFT Inverse FFT (Fast Fourier Transform) IP Internet Protocol IQ In-phase/Quadrature components IRD Integrated Receiver Decoder ISO International Organization for Standardization ISSY Input Stream SYnchronizer ITU International Telecommunication Union LAT Link Available Time LDPC Low Density Parity Check (codes) ETSI ETSI TR 101 290 V1.4.1 (2020-06) 17 LO Local Oscillator LP Low Priority LUAT Link Unavailable Time MDI Media Delivery Index MED Maximum Excess Delay MER Modulation Error Ratio MERV Modulation Error Ratio - Voltage MFN Multi-Frequency Network MG Measurement Guidelines MGPR MISO Group Power Ratio MI Modulator Interface MIP Mega-frame Initialization Packet MISO Multiple Input Single Output MLR Media Loss Rate MMDS Microwave Multi-point Distribution Systems (or Multi-channel Multi-point Distribution Systems) MPEG Moving Picture Experts Group MPTS Multi-Program Transport Stream MR Nominal Media Rate MTU Maximum Transmission Unit MUX Multiplex MVDS Multi-point Video Distribution Systems NIT Network Information Table NM Noise Margin OB Occupied Bandwidth OFDM Orthogonal Frequency Division Multiplex PAPR Peak to Average Power Ratio PAT Program Association Table PCR Program Clock Reference PDH Plesiochronous Digital Hierarchy PER Packet Error Rate PID Packet Identifier PJ Phase Jitter PLL Phase Locked Loop PLP Physical Layer Pipe PMT Program Map Table PRBS Pseudo Random Binary Sequence PSI MPEG-2 Program Specific Information NOTE: As defined in ISO/IEC 13818-1 [i.1]. PTS Presentation Time Stamps QAM Quadrature Amplitude Modulation QAM-M QAM systems with e.g. M = 16, 32 and 64 QB Bit error probability QE Quadrature Error QEF Quasi Error Free QPSK Quaternary Phase Shift Keying RBA Receiver Buffer Assumptions RBM Receiver Buffer Model RBW Resolution Bandwidth RC FEC rate REC Receiver RF Radio Frequency RFC IETF Request For Comments RMS Root Mean Square RS Reed-Solomon RST Running Status Table NOTE: See ETSI EN 300 468 [i.7]. RTE Residual Target Error RTP Real Time Protocol ETSI ETSI TR 101 290 V1.4.1 (2020-06) 18 SDH Synchronous Digital Hierarchy SDP Severely Disturbed Period SDT Service Description Table SEP Symbol Error Probability SER Symbol Error Rate SES Seriously Errored Second SETI Severely Errored Time Interval SFN Single Frequency Network SI Service Information SINR Signal to Interference Noise Ratio SMATV Satellite Master Antenna TeleVision SMPTE Society of Motion Picture and Television Engineers SNR Signal-to-Noise Ratio ST Stuffing Table STD System Target Decoder STE System Target Error STS Synchronization Time Stamp SUS Severely Uncorrectable Second SUTI Severely Uncorrectable Time Interval SYNC Synchronization TDT Time and Date Table TEV Target Error Vector TFS Time-Frequency-Slicing TH Transport Header TOT Time Offset Table TPS Transmission Parameter Signalling TS Transport Stream TSTD Transport Stream Description Table TU Typical Urban TV TeleVision TX-SIG Transmitter Signalling UAT Unavailable Time UDP User Datagram Protocol UHF Ultra-High Frequency UI Unit Interval uimsbf unsigned integer, most significant bit first UP Uncorrectable Packet US Uncorrectable Second UTC Universal Time Co-ordinated UTI Uncorrectable Time Interval VB Virtual Buffer VBR Variable Bit Rate VBW Video Bandwidth |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 4 General | The Digital Video Broadcasting (DVB) set of digital TV standards specify baseline systems for various transmission media: satellite, cable, terrestrial, etc. Each baseline system standard defined the channel coding and modulation schemes for that transmission medium. The source coding was adapted from the MPEG-2 standard. The design of these new systems has created a demand for a common understanding of measurement techniques and the interpretation of measurement results. The present document is an attempt to give recommendations in this field by defining a number of measurement techniques in such detail that the results are actually comparable as long as the measurement is carried out in compliance with the given definition. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 19 Engineers seeking to apply the methods described in the present document should be familiar with the standards for the respective baseline systems. Although most of the parameters specified in the present document are well known in communications, most of them should be interpreted with respect to the new environment, especially the transmission of digital TV signals or other related services. The inclusion of each parameter in the present document is based on requirements from those who envisage having to work alongside the defined procedures. This includes network operators and providers of equipment for network installation, as well as manufacturers of Integrated Receiver Decoders (IRDs) or test and measurement equipment. The recommendations of the present document can be used: - to set-up test beds or laboratory equipment for testing hardware for digital TV and other related services; - to set these instruments to the appropriate parameters; - to obtain unambiguous results that can be directly compared with results from other test set-ups; - to form a potential basis for communicating results in an efficient way by using the definitions in the present document as references. They are not intended to describe a set of compulsory tests. The recommendations are grouped in several clauses. Since the MPEG-2 TS is the signal format used for the inputs and outputs of all baseline systems, clause 5 is devoted to the description of checking procedures for those parameters which are accessible in the TS packet header, i.e. without decoding scrambled or encrypted data. The aim of these tests is the provision of a simple and fast health check. It is meant neither as a MPEG-2 conformance test nor as a compliance test for all DVB related issues. Clause 6 contains the parameters which are commonly addressed by various transmission media. For example, the measurement of the availability of transmission systems or links falls into this category, and it may be desirable to have the same definition for availability independent of the actual system in use. Clauses 7 and 8 address the parameters which are specific for cable and satellite, DVB-C and DVB-S, they are also applicable to SMATV systems, DVB-CS, and possibly MMDS systems such as DVB-MC and DVB-MS. Clause 9 addressed parameters specific to the terrestrial DVB environment (DVB-T). Clauses 6, 7, 8, and 9 of the present document follow the same structure. For each parameter there is a description of the purpose of the recommended measurement procedure, the interface to which the measurement instrument should be applied, and a description of the actual method of the measurement itself. Apart from these clauses a number of annexes are included, containing recommendations for general aspects, examples of test set-ups and certain requirements for the test and measurement equipment. If the interfaces for a described measurement procedure are to be found within the transmitter, the notation is provided in accordance with figures 4.1 and 9.1 for DVB-T (the 1st generation terrestrial DVB system). If the interfaces for the described measurement procedures are to be found within the receiver (test receiver or IRD), the notation is provided in accordance with figures 4.2 and 9.2 for DVB-T. These figures illustrate the general cases of a DVB transmitter and receiver of the 1st generation systems, although certain functional blocks only appear in certain systems. Most of the parameters can be measured with standard equipment such as spectrum analysers or constellation analysers. Other parameters are defined in a new way as a request to test and measurement equipment manufacturers to integrate this functionality in their products. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 20 Figure 4.1: Transmitter block diagram Figure 4.2: Receiver block diagram The clauses 11 and 12 address two of the DVB transmission systems of the 2nd generation, DVB-T2 and DVB-C2. In clause 11.2 includes the definition of measurement parameters for the DVB-T2 Modulator Interface DVB-T2 MI. The block diagrams for these 2nd generation transmission systems can be found in the respective clauses. 5 Measurement and analysis of the MPEG-2 Transport Stream |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.1 General | The MPEG-2 Transport Stream (TS) is the specified input and output signal for all the baseline systems, i.e. for satellite, cable, SMATV, MMDS/MVDS and terrestrial distribution, which are defined in the DVB world so far. Therefore these interfaces are accessible in the transmission chain. Direct access is given on the transmitter side at the input of the respective baseline system. At other interfaces where the signal occurs in modulated form, access is possible by an appropriate demodulator that provides the TS interface as an output for further measurements. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.2 List of parameters recommended for evaluation | |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.2.0 Introduction | The present document recommends in this clause a set of syntax and information consistency tests that can be applied to an MPEG-2 TS at the parallel interface, or either of the serial interfaces defined in EN 50083-9 [i.10]. The following assumptions and guiding principles were used in developing these tests: - the tests are mainly intended for continuous or periodic monitoring of MPEG-2 TSs in an operational environment; ETSI ETSI TR 101 290 V1.4.1 (2020-06) 21 - these tests are primarily designed to check the integrity of a TS at source; clause 5.3 covers other aspects of TSs in networks including impairments created by transport systems; - the general aim of the tests is to provide a "health check" of the most important elements of the TS. The list of the tests is not exhaustive; - the tests are consistent with the MPEG-2 Conformance tests defined in ISO/IEC 13818-4 [i.2], they do not replace them; - the tests are consistent with the DVB-SI documents (ETSI EN 300 468 [i.7], ETSI TR 101 211 [i.8]), they do not replace them. MPEG-2 and DVB-SI reserved values in the TS do not cause a test error indication. In general the tests are performed on TS header information so that they are still valid when conditional access algorithms are applied, however a few of the tests may only be valid for an unscrambled or descrambled TS. The tests are not dependant on any decoder implementation for consistency of results. The MPEG-2 T-STD model constraints, as defined in ISO/IEC 13818-1 [i.1] (MPEG-2 Systems), should be satisfied as specified in ISO/IEC 13818-4 [i.2] (MPEG-2 Compliance). Off-line tests are performed under stable conditions, no discontinuity or dynamic change can occur during an off-line test process. Other digital performance parameters such as BER are not considered in this clause. This clause tabulates the parameters which are recommended for continuous or periodic monitoring of the MPEG-2 TS. The tests are grouped into three tables according to their importance for monitoring purposes. The first table lists a basic set of parameters which are considered necessary to ensure that the TS can be decoded. The second table lists additional parameters which are recommended for continuous monitoring. The third table lists optional additional parameters which could be of interest for certain applications. Any test equipment intended for the evaluation of these parameters should report test results by means of the indicators itemized in the second column of the tables under exactly the preconditions described in the third column of the tables. If an indicator is set, then the TS is in error. However, since the indicators do not cover the entire range of possible errors, it cannot be concluded that there is no error if the indicator is not set. If indicator 1.1 is activated then all other indicators are invalid. Each indicator is activated only as long as at least one of the described preconditions is fulfilled. NOTE: In the case of indicators requiring a minimum repetition rate of sections, it is intended that each and every section that is present for this table should have the stated repetition rate. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 22 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.2.1 First priority: necessary for de-codability (basic monitoring) | Table 5.0a: MPEG-2 TS parameters of 1st priority No. Indicator Precondition Reference 1.1 TS_sync_loss Loss of synchronization with consideration of hysteresis parameters ISO/IEC 13818-1 [i.1], clause 2.4.3.3 and annex G.1 1.2 Sync_byte_error Sync_byte not equal 0x47 ISO/IEC 13818-1 [i.1], clause 2.4.3.3 1.3 PAT_error PID 0x0000 does not occur at least every 0,5 s a PID 0x0000 does not contain a table_id 0x00 (i.e. a PAT) Scrambling_control_field is not 00 for PID 0x0000 ISO/IEC 13818-1 [i.1], clauses 2.4.4.3, 2.4.4.4 1.3.a (note 1) PAT_error_2 Sections with table_id 0x00 do not occur at least every 0,5 s on PID 0x0000. Section with table_id other than 0x00 found on PID 0x0000. Scrambling_control_field is not 00 for PID 0x0000 ETSI TS 101 154 [i.30], clause 4.1.7 ISO/IEC 13818-1 [i.1], clauses 2.4.4.3, 2.4.4.4 1.4 Continuity_ count_error Incorrect packet order a packet occurs more than twice lost packet ISO/IEC 13818-1 [i.1], clauses 2.4.3.2, 2.4.3.3 1.5 PMT_error Sections with table_id 0x02, (i.e. a PMT), do not occur at least every 0,5 s on the PID which is referred to in the PAT Scrambling_control_field is not 00 for all PIDs containing sections with table_id 0x02 (i.e. a PMT) ISO/IEC 13818-1 [i.1], clauses 2.4.4.3, 2.4.4.4, 2.4.4.8 1.5.a (note 2) PMT_error_2 Sections with table_id 0x02, (i.e. a PMT), do not occur at least every 0,5 s on each program_map_PID which is referred to in the PAT Scrambling_control_field is not 00 for all packets containing information of sections with table_id 0x02 (i.e. a PMT) on each program_map_PID which is referred to in the PAT ETSI TS 101 154 [i.30], clause 4.1.7 (note 3) ISO/IEC 13818-1 [i.1], clauses 2.4.4.3, 2.4.4.4, 2.4.4.8 1.6 PID_error Referred PID does not occur for a user specified period. ISO/IEC 13818-1 [i.1], clause 2.4.4.8 NOTE 1: Recommended for future implementations as a replacement of 1.3. NOTE 2: Recommended for future implementations as a replacement of 1.5; this excludes specifically network_PIDs. NOTE 3: In ETSI TS 101 154 [i.30], it is recommended that the interval between two sections should not exceed 100 ms. For many applications it may be sufficient to check that the interval is no longer than 0,5 s. TS_sync_loss The most important function for the evaluation of data from the MPEG-2 TS is the sync acquisition. The actual synchronization of the TS depends on the number of correct sync bytes necessary for the device to synchronize and on the number of distorted sync bytes which the device cannot cope with. It is proposed that five consecutive correct sync bytes (ISO/IEC 13818-1 [i.1], clause G.1) should be sufficient for sync acquisition, and two or more consecutive corrupted sync bytes should indicate sync loss. After synchronization has been achieved the evaluation of the other parameters can be carried out. Sync_byte_error The indicator "Sync_byte_error" is set as soon as the correct sync byte (0x47) does not appear after 188 or 204 bytes. This is fundamental because this structure is used throughout the channel encoder and decoder chains for synchronization. It is also important that every sync byte is checked for correctness since the encoders may not necessarily check the sync byte. Apparently some encoders use the sync byte flag signal on the parallel interface to control randomizer re-seeding and byte inversion without checking that the corresponding byte is a valid sync byte. PAT_error The Program Association Table (PAT), which only appears in PID 0x0000 packets, tells the decoder what programs are in the TS and points to the Program Map Tables (PMT) which in turn point to the component video, audio and data streams that make up the program (figure 5.2). If the PAT is missing then the decoder can do nothing, no program is decodable. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 23 Nothing other than a PAT should be contained in a PID 0x0000. PAT_error_2 The reworded description of the error in PAT_error_2 refers to the possibility that the Program Association Table may consist of several (consecutive) sections with the same table_id 0x00. Continuity_count_error For this indicator three checks are combined. The preconditions "Incorrect packet order" and "Lost packet" could cause problems for IRD which are not equipped with additional buffer storage and intelligence. It is not necessary for the test equipment to distinguish between these two preconditions as they are logically OR-ed, together with the third precondition, into one indicator. The latter is also covering the packet loss that may occur on ATM links, where one lost ATM packet would cause the loss of a complete MPEG-2 packet. The precondition "a packet occurs more than twice" may be symptomatic of a deeper problem that the service provider would like to keep under observation. PMT_error The Program Association Table (PAT) tells the decoder how many programs there are in the stream and points to the PMTs which contain the information where the parts for any given event can be found. Parts in this context are the video stream (normally one) and the audio streams and the data stream (e.g. Teletext). Without a PMT the corresponding program is not decodable. PID_error It is checked whether there exists a data stream for each PID that occurs. This error might occur where TS are multiplexed, or demultiplexed and again remultiplexed. The user specified period should not exceed 5 s for video or audio PIDs (see note). Data services and audio services with ISO 639 [i.17] language descriptor with type greater than '0' should be excluded from this 5 s limit. NOTE: For PIDs carrying other information such as sub-titles, data services or audio services with ISO 639 [i.17] language descriptor with type greater than '0', the time between two consecutive packets of the same PID may be significantly longer. In principle, a different user specified period could be defined for each PID. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.2.2 Second priority: recommended for continuous or periodic monitoring | Table 5.0b: MPEG-2 TS parameters of 2nd priority No. Indicator Precondition Reference 2.1 Transport_error Transport_error_indicator in the TS-Header is set to "1" ISO/IEC 13818-1 [i.1]: clauses 2.4.3.2, 2.4.3.3 2.2 CRC_error CRC error occurred in CAT, PAT, PMT, NIT, EIT, BAT, SDT or TOT table ISO/IEC 13818-1 [i.1]: clauses 2.4.4, annex A ETSI EN 300 468 [i.7]: clause 5.2 2.3 PCR_error (see notes 1 and 2) PCR discontinuity of more than 100 ms occurring without specific indication. Time interval between two consecutive PCR values more than 100 ms ISO/IEC 13818-1 [i.1]: clauses 2.4.3.4, 2.4.3.5 ISO/IEC 13818-4 [i.2]: clause 9.11.3 ETSI TS 101 154 [i.30]: clause 4.1.5.3 2.3a PCR_repetition_ error (see notes 1 and 2) Time interval between two consecutive PCR values more than 100 ms ETSI TS 101 154 [i.30]: clause 4.1.5.3 2.3b PCR_discontinuity_ indicator_error The difference between two consecutive PCR values (PCRi+1 – PCRi) is outside the range of 0...100 ms without the discontinuity_indicator set ISO/IEC 13818-1 [i.1]: clauses 2.4.3.4, 2.4.3.5 ISO/IEC 13818-4 [i.2]: clause 9.1.1.3 2.4 PCR_accuracy_ error PCR accuracy of selected programme is not within ±500 ns ISO/IEC 13818-1 [i.1]: clause 2.4.2.2 2.5 PTS_error (see note 3) PTS repetition period more than 700 ms ISO/IEC 13818-1 [i.1]: clauses 2.4.3.6, 2.4.3.7, 2.7.4 ETSI ETSI TR 101 290 V1.4.1 (2020-06) 24 No. Indicator Precondition Reference 2.6 CAT_error Packets with transport_scrambling_control not 00 present, but no section with table_id = 0x01 (i.e. a CAT) present Section with table_id other than 0x01 (i.e. not a CAT) found on PID 0x0001 ISO/IEC 13818-1 [i.1]: clause 2.4.4 NOTE 1: The old version of PCR_error (2.3) is a combination of the more specific errors PCR_repetition_error (2.3.a) and PCR_discontinuity_indicator_error (2.3.b) by a logical 'or' function. It is kept in the present document for reasons of consistency of existing implementations. For new implementations it is recommended that the indicators 2.3.a and 2.3.b are used only. NOTE 2: The limitation to 40 ms in the 'Preconditions' of 2.3 PCR_error and 2.3a PCR_repetition_error was removed from ETSI TS 101 154 [i.30] in 2005. The respective clause there now refers only to the 100 ms limitation in [i.1] which is recommended to be applied generally. NOTE 3: The limitation to 700 ms should not be applied to still pictures. Transport_error The primary Transport_error indicator is Boolean, but there should also be a resettable binary counter which counts the erroneous TS packets. This counter is intended for statistical evaluation of the errors. If an error occurs, no further error indication should be derived from the erroneous packet. There may be value in providing a more detailed breakdown of the erroneous packets, for example, by providing a separate Transport_error counter for each program stream or by including the PID of each erroneous packet in a log of Transport_error events. Such extra analysis is regarded as optional and not part of this recommendation. CRC_error The CRC check for the CAT, PAT, PMT, NIT, EIT, BAT, SDT and TOT indicates whether the content of the corresponding table is corrupted. In this case no further error indication should be derived from the content of the corresponding table. PCR_error The PCRs are used to re-generate the local 27 MHz system clock. If the PCR do not arrive with sufficient regularity then this clock may jitter or drift. The receiver/decoder may even go out of lock. In DVB a repetition period of not more than 100 ms is permitted, previously a maximum of 40ms was recommended (see note 2 in table 5.0b). PCR_repetition_error The PCRs are used to re-generate the local 27 MHz system clock. If the PCR do not arrive with sufficient regularity then this clock may jitter or drift. The receiver/decoder may even go out of lock. In DVB a repetition period of not more than 100 ms is permitted, previously a maximum of 40ms was recommended (see note 2 in table 5.0b). The error indication that may result from the check of this repetition period should be called PCR_repetition_error in future implementations (after the release of the present document). PCR_discontinuity_indicator_error The PCR_discontinuity_indicator_error is set in the case that a discontinuity of the PCR values occurs that has not been signalled appropriately by the discontinuity indicator. The usage of this indicator is recommended for future implementations (after the release of the present document). PCR_accuracy_error The accuracy of ±500 ns is intended to be sufficient for the colour subcarrier to be synthesized from system clock. This test should only be performed on a constant bitrate TS as defined in ISO/IEC 13818-1 [i.1] clause 2.4.2.2. Further information on PCR jitter measurements is given in clause 5.3.2. PTS_error The Presentation Time Stamps (PTS) should occur at least every 700 ms (see note 3 in table 5.0b). They are only accessible if the TS is not scrambled. CAT_error The CAT is the pointer to enable the IRD to find the EMMs associated with the CA system(s) that it uses. If the CAT is not present, the receiver is not able to receive management messages. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 25 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.2.3 Third priority: application dependant monitoring | Table 5.0c: MPEG-2 TS parameters of 3rd priority No. Indicator Precondition Reference 3.1 NIT_error (note 2) Section with table_id other than 0x40 or 0x41 or 0x72 (i. e. not an NIT or ST) found on PID 0x0010 No section with table_id 0x40 or 0x41 (i.e. an NIT) in PID value 0x0010 for more than 10 s. ETSI EN 300 468 [i.7], clause 5.2.1 ETSI TR 101 211 [i.8], clauses 4.1, 4.4 3.1.a NIT_actual_error Section with table_id other than 0x40 or 0x41 or 0x72 (i.e. not an NIT or ST) found on PID 0x0010 No section with table_id 0x40 (i.e. an NIT_actual) in PID value 0x0010 for more than 10 s. Any two sections with table_id = 0x40 (NIT_actual) occur on PID 0x0010 within a specified value (25 ms or lower). ETSI EN 300 468 [i.7], clause 5.2.1, 5.1.4 ETSI TR 101 211 [i.8], clauses 4.1, 4.4 3.1.b NIT_other_error Interval between sections with the same section_number and table_id = 0x41 (NIT_other) on PID 0x0010 longer than a specified value (10 s or higher). ETSI TR 101 211 [i.8], clause 4.4 3.2 SI_repetition_ error Repetition rate of SI tables outside of specified limits. ETSI EN 300 468 [i.7], clause 5.1.4 ETSI TR 101 211 [i.8], clause 4.4 3.3 Buffer_error TB_buffering_error overflow of transport buffer (TBn) TBsys_buffering_error overflow of transport buffer for system information (Tbsys) MB_buffering_error overflow of multiplexing buffer (MBn) or if the vbv_delay method is used: underflow of multiplexing buffer (Mbn) EB_buffering_error overflow of elementary stream buffer (EBn) or if the leak method is used: underflow of elementary stream buffer (EBn) though low_delay_flag and DSM_trick_mode_flag are set to 0 else (vbv_delay method) underflow of elementary stream buffer (EBn) B_buffering_error overflow or underflow of main buffer (Bn) Bsys_buffering_error overflow of PSI input buffer (Bsys) ISO/IEC 13818-1 [i.1], clause 2.4.2.3 ISO/IEC 13818-4 [i.2], clauses 9.11.2, 9.1.4 3.4 Unreferenced_PID PID (other than PAT, CAT, CAT_PIDs, PMT_PIDs, NIT_PID, SDT_PID, TDT_PID, EIT_PID, RST_PID, reserved_for_future_use PIDs, or PIDs user defined as private data streams) not referred to by a PMT within 0,5 s (note 1). ETSI EN 300 468 [i.7], clause 5.1.3 3.4.a Unreferenced_PID PID (other than PMT_PIDs, PIDs with numbers between 0x00 and 0x1F or PIDs user defined as private data streams) not referred to by a PMT or a CAT within 0,5 s. ETSI EN 300 468 [i.7], clause 5.1.3 3.5 SDT_error (note 3) Sections with table_id = 0x42 (SDT, actual TS) not present on PID 0x0011 for more than 2 s Sections with table_ids other than 0x42, 0x46, 0x4A or 0x72 found on PID 0x0011. ETSI EN 300 468 [i.7], clause 5.1.3 ETSI TR 101 211 [i.8], clauses 4.1, 4.4 3.5.a SDT_actual_error Sections with table_id = 0x42 (SDT, actual TS) not present on PID 0x0011 for more than 2 s Sections with table_ids other than 0x42, 0x46, 0x4A or 0x72 found on PID 0x0011. Any two sections with table_id = 0x42 (SDT_actual) occur on PID 0x0011 within a specified value (25 ms or lower). ETSI EN 300 468 [i.7], clauses 5.2.3, 5.1.4 ETSI TR 101 211 [i.8], clauses 4.1, 4.4 ETSI ETSI TR 101 290 V1.4.1 (2020-06) 26 No. Indicator Precondition Reference 3.5.b SDT_other_error Interval between sections with the same section_number and table_id = 0x46 (SDT, other TS) on PID 0x0011 longer than a specified value (10s or higher). ETSI TR 101 211 [i.8], clause 4.4 3.6 EIT_error (note 4) Sections with table_id = 0x4E (EIT-P/F, actual TS) not present on PID 0x0012 for more than 2 s Sections with table_ids other than in the range 0x4E - 0x6F or 0x72 found on PID 0x0012. ETSI EN 300 468 [i.7], clause 5.1.3 ETSI TR 101 211 [i.8], clauses 4.1, 4.4 3.6.a EIT_actual_error Section '0' with table_id = 0x4E (EIT-P, actual TS) not present on PID 0x0012 for more than 2 s Section '1' with table_id = 0x4E (EIT-F, actual TS) not present on PID 0x0012 for more than 2 s Sections with table_ids other than in the range 0x4E - 0x6F or 0x72 found on PID 0x0012. Any two sections with table_id = 0x4E (EIT-P/F, actual TS) occur on PID 0x0012 within a specified value (25 ms or lower). ETSI EN 300 468 [i.7], clauses 5.2.4, 5.1.4 ETSI TR 101 211 [i.8], clauses 4.1, 4.4 3.6.b EIT_other_error Interval between sections '0' with table_id = 0x4F (EIT-P, other TS) on PID 0x0012 longer than a specified value (10 s or higher); Interval between sections '1' with table_id = 0x4F (EIT-F, other TS) on PID 0x0012 longer than a specified value (10 s or higher). ETSI TR 101 211 [i.8], clause 4.4 3.6.c EIT_PF_error If either section ('0' or '1') of each EIT P/F sub table is present both should exist. Otherwise EIT_PF_error should be indicated. ETSI EN 300 468 [i.7], clause 5.2.4. 3.7 RST_error Sections with table_id other than 0x71 or 0x72 found on PID 0x0013. Any two sections with table_id = 0x71 (RST) occur on PID 0x0013 within a specified value (25 ms or lower). ETSI EN 300 468 [i.7], clause 5.1.3 3.8 TDT_error Sections with table_id = 0x70 (TDT) not present on PID 0x0014 for more than 30 s Sections with table_id other than 0x70, 0x72 (ST) or 0x73 (TOT) found on PID 0x0014. Any two sections with table_id = 0x70 (TDT) occur on PID 0x0014 within a specified value (25 ms or lower). ETSI EN 300 468 [i.7], clauses 5.1.3, 5.2.6 ETSI TR 101 211 [i.8], clauses 4.1, 4.4 3.9 Empty_buffer_error Transport buffer (TBn) not empty at least once per second or transport buffer for system information (TBsys) not empty at least once per second or if the leak method is used multiplexing buffer (MBn) not empty at least once per second. ISO/IEC 13818-1 [i.1], clauses 2.4.2.3, 2.4.2.6 ISO/IEC 13818-9 [i.3], annex E ISO/IEC 13818-4 [i.2], clauses 9.1.1.2, 9.1.4 3.10 Data_delay_error Delay of data (except still picture video data) through the TSTD buffers superior to 1 second; or delay of still picture video data through the TSTD buffers superior to 60 s. ISO/IEC 13818-1 [i.1], clauses 2.4.2.3, 2.4.2.6 ETSI ETSI TR 101 290 V1.4.1 (2020-06) 27 No. Indicator Precondition Reference NOTE 1: It is assumed that transition states are limited to 0,5 s, and these transitions should not cause error indications. NOTE 2: The old version of NIT_error (3.1) has been split into the more specific errors NIT_actual_error (3.1.a) and NIT_other_error (3.1.b). The old version is kept in the document for reasons of consistency of existing implementations. For new implementations it is recommended that the indicators 3.1.a and 3.1.b are used only. NOTE 3: The old version of SDT_error (3.5) has been split into the more specific errors SDT_actual_error (3.5.a) and SDT_other_error (3.5.b). The old version is kept in the present document for reasons of consistency of existing implementations. For new implementations it is recommended that the indicators 3.5.a and 3.5.b are used only. NOTE 4: The old version of EIT_error (3.6) has been split into the more specific errors EIT_actual_error (3.6.a), EIT_other_error (3.6.b) and EIT_PF_error (3.6.c). The old version is kept in the present document for reasons of consistency of existing implementations. For new implementations it is recommended that the indicators 3.6.a, 3.6.b and 3.6.c are used only. NIT_error [i.1] Network Information Tables (NITs) as defined by DVB contain information on frequency, code rates, modulation, polarization, etc. of various programs which the decoder can use. It is checked whether NITs are present in the TS and whether they have the correct PID. NIT_actual_error Network Information Tables (NITs) as defined by DVB contain information on frequency, code rates, modulation, polarization, etc. of various programs which the decoder can use. It is checked whether the NIT related to the respective TS is present in this TS and whether it has the correct PID. NIT_other_error Further Network Information Tables (NITs) can be present under a separate PID and refer to other TSs to provide more information on programmes available on other channels. Their distribution is not mandatory and the checks should only be performed if they are present. SI_repetition_error For SI tables a maximum and minimum periodicity are specified in ETSI EN 300 468 [i.7] and ETSI TR 101 211 [i.8]. This is checked for this indicator. This indicator should be set in addition to other indicators of repetition errors for specific tables. Buffer_error For this indicator a number of buffers of the MPEG-2 reference decoder are checked whether they would have an underflow or an overflow. Unreferenced_PID Each non-private program data stream should have its PID listed in the PMTs. SDT_error The SDT describes the services available to the viewer. It is split into sub-tables containing details of the contents of the current TS (mandatory) and other TS (optional). Without the SDT, the IRD is unable to give the viewer a list of what services are available. It is also possible to transmit a BAT on the same PID, which groups services into "bouquets". SDT_actual_error The SDT (Service Description Table) describes the services available to the viewer. It is split into sub-tables containing details of the contents of the current TS (mandatory) and other TS (optional). Without the SDT, the IRD is unable to give the viewer a list of what services are available. It is also possible to transmit a BAT on the same PID, which groups services into "bouquets". SDT_other_error This check is only performed if the presence of a SDT for other TSs has been established. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 28 EIT_error The EIT (Event Information Table) describes what is on now and next on each service, and optionally details the complete programming schedule. The EIT is divided into several sub-tables, with only the "present and following" information for the current TS being mandatory. The EIT schedule information is only accessible if the TS is not scrambled. EIT_actual_error The EIT (Event Information Table) describes what is on now and next on each service, and optionally details the complete programming schedule. The EIT is divided into several sub-tables, with only the "present and following" information for the current TS being mandatory. If there are no 'Present' or 'Following' events, empty EIT sections will be transmitted according to ETSI TR 101 211 [i.8]. The EIT schedule information is only accessible if the TS is not scrambled. EIT_other_error This check is only performed if the presence of an EIT for other TSs has been established. RST_error The RST is a quick updating mechanism for the status information carried in the EIT. TDT_error The TDT carries the current UTC time and date information. In addition to the TDT, a TOT can be transmitted which gives information about a local time offset in a given area. The carriage of the following tables: - NIT_other; - SDT_other; - EIT_P/F_other; - EIT_schedule_other; - EIT_schedule_actual; is optional and therefore these tests should only be performed when the respective table is present. When these tables are present this will be done automatically by measuring the interval rather than the occurrence of the first section. As a further extension of the checks and measurements mentioned above an additional test concerning the SI is recommended: all mandatory descriptors in the SI tables should be present and the information in the tables should be consistent. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 29 Figure 5.1: Indicators related to TS syntax Figure 5.2: Indicators related to TS structure ETSI ETSI TR 101 290 V1.4.1 (2020-06) 30 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3 Measurement of MPEG-2 Transport Streams in networks | |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.1 Introduction | A MPEG-2 Transport Stream that is transmitted over any real network, is exposed to certain effects caused by the network components which are not ideally transparent. One of the pre-dominant effects is the acquisition of jitter in relation to the PCR values and their position in the TS. The parameters defined in clause 5.3.2 describe the various jitter components which can be differentiated by demarcation frequencies. For the measurement of bitrates of Transport Streams, the requirements vary significantly for constant bitrate TS and partial TS/variable bitrate TS. The application of statistical multiplexers led to more dynamic variations in the bitrate, especially of the video components. Other services such as opportunistic data transmission, have typical features which again differ in terms of occurrence or presence of the service and the variation of bitrates. In clause 5.3.3 several profiles are defined to accommodate the majority of such applications, and which can be applied for monitoring and localization of failures. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.2 System clock and PCR measurements | |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.2.1 Reference model for system clock and PCR measurements | This clause presents a reference model for any source of a transport stream (TS) concerning the generation of PCR values and delivery delays. It models all the timing effects visible at the TS interface point. It is not intended to represent all the mechanisms by which these timing effects could arise in real systems. Reference clock f = 27MHz + fdev(t) PCR counter PCR inaccuracy source Mp,i Np,i + D + Ji Delivery timing delay A B C Figure 5.3: Reference model Reference points are indicated by dashed lines. This is a model of an encoder/multiplexer (up to reference point B) and a physical delivery mechanism or communications network (between reference points B and C). The components of the model to the left of reference point B are specific to a single PCR PID. The components of the model to the right of reference point B relate to the whole Transport Stream. Measuring equipment can usually only access the TS at reference point C. The model consists of a system clock frequency oscillator with a nominal frequency of 27 MHz, but whose actual frequency deviates from this by a function fdev(p, t). This function depends on the time (t) and is specific to a single PCR PID (p). The "Frequency Offset PCR_FO" measures the value of fdev(p, t). The "Drift Rate PCR_DR" is the rate of change with time of fdev(p, t). ETSI ETSI TR 101 290 V1.4.1 (2020-06) 31 The system clock frequency oscillator drives a PCR counter which generates an idealized PCR count, Np,i. p refers to the specific PCR PID p and i refers to the bit position in the transport stream. To this is added a value from a PCR inaccuracy source, Mp,i to create the PCR value seen in the stream, Pp,i. The simple relationship between these values is: i p i p i p M N P , , , + = (1) Mp,i represents the "Accuracy PCR_AC". The physical delivery mechanism or communications network beyond point B introduces a variable delay between the departure time Ti and the arrival time Ui of bits: i i i J D T U + = − (2) In the case of a PCR, Ui is the time of arrival of the last bit of the last byte containing the PCR base (ISO/IEC 13818-1 [i.1], clause 2.4.3.5). D is a constant representing the mean delay through the communications network. Ji represents the jitter in the network delay and its mean value over all time is defined to be zero. Ji + Mp,i is measured as the "Overall Jitter PCR_OJ". In the common case where the Transport Stream is constant bitrate, at reference point B the Transport Stream is being transmitted at a constant bitrate Rnom. It is important to note that in this reference model this bitrate is accurate and constant; there is no error contribution from varying bitrate. This gives an additional equation for the departure time of packets: nom i R i T T + = 0 (3) T0 is a constant representing the time of departure of the zero'th bit. Combining equations 2 and 3 the arrival time is: i nom i J D R i T U + + + = 0 (4) |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.2.2 Measurement descriptions | The following measurements require a demarcation frequency for delimiting the range of drift rate and jitter frequencies of the timing variations of PCRs and/or TSs. The demarcation frequency used should be chosen from table 5.1 and indicated with the measurement results. Table 5.1: Profiles for jitter and drift rate measurements Profile Demarcation frequency Comments MGF1 10 mHz This profile is provided to give the total coverage of frequency components included in the timing impairments of PCR related measurements. This profile provides the most accurate results in accordance with the limits specified in ISO/IEC 13818-1 [i.1], clause 2.4.2.1. If jitter or drift rate measurements are found out of specification when using other profiles, it is suggested to use this one for better accuracy. MGF2 100 mHz This profile is accounting for intermediate benefits between the profiles MGF1 and MGF3, by giving reasonable measurement response as well as reasonable account for low frequency components of the timing impairments. MGF3 1 Hz This profile provides faster measurement response by taking in account only the highest frequency components of the timing impairments. This profile is expected to be sufficient in many applications. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 32 Profile Demarcation frequency Comments MGF4 Manufacturer defined This profile will provide any benefit that the manufacturer may consider as useful when it is designed and implemented in a measurement instrument. The demarcation frequency has to be supplied with the measurement result. Optionally any other data that the manufacturer may consider to be relevant may be supplied. For testing against ISO/IEC 13818-9 [i.3] (±25 µs jitter limit) a demarcation frequency of 2 mHz is required. A filter for such demarcation may be implemented under this MGF4 profile. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.2.3 Program Clock Reference - Frequency Offset PCR_FO | Definition PCR_FO is defined as the difference between the program clock frequency and the nominal clock frequency (measured against a reference which is not PCR derived, neither TS derived). The units for the parameter PCR_FO should be in Hz according to: • Measured Frequency - Nominal Frequency, • or in ppm expressed as: − [Measured Frequency (in Hz) - Nominal Frequency(in Hz)]/Nominal Frequency (in MHz). Purpose The original frequency of the clock used in the digital video format before compression (program clock) is transmitted to the final receiver in form of numerical values in the PCR fields. The tolerance as specified by ISO/IEC 13818-1 [i.1] clause 2.4.2.1 is ±810 Hz or ±30 ppm. Interface A, Z 5.3.2.4 Program Clock Reference – Drift Rate PCR_DR Definition PCR_DR is defined as the first derivative of the frequency and is measured on the low frequency components of the difference between the program clock frequency and the nominal clock frequency (measured against a reference which is not PCR derived, neither TS derived). The format of the parameter PCR_DR should be in mHz/s (@ 27 MHz) or ppm/hour. Purpose The measurement is designed to verify that the frequency drift, if any, of the program clock frequency is below the limits set by ISO/IEC 13818-1 [i.1]. This limit is effective only for the low frequency components of the variations. The tolerance as specified by ISO/IEC 13818-1 [i.1] is ±75 mHz/s@ 27 MHz or ±10 ppm/hour. Interface A, Z NOTE: A break frequency of 10 mHz is recommended for the separation of PCR_jitter (higher frequencies) and PCR_drift (lower frequencies). See also MGF1 in Table 5.1. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.2.5 Program Clock Reference - Overall Jitter PCR_OJ | Definition PCR_OJ is defined as the instantaneous measurement of the high frequency components of the difference between when a PCR should have arrived at a measurement point (based upon previous PCR values, its own value and a reference which is not PCR or TS derived) and when it did arrive. The format of the parameter PCR_OJ should be in nanoseconds. Purpose The PCR_OJ measurement is designed to account for all cumulative errors affecting the PCR values during program stream generation, multiplexing, transmission, etc. All these effects appear as jitter at the receiver but they are a combination of PCR inaccuracies and jitter in the transmission. This value can be compared against the maximum error specification by ISO/IEC 13818-1 [i.1] for PCR Accuracy of ±500 ns only if the jitter in the transmission is assumed to be zero. Interface A, Z NOTE: A break frequency of 10 mHz is recommended for the separation of PCR_jitter (higher frequencies) and PCR_drift (lower frequencies). See also MGF1 in table 5.1. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 33 5.3.2.6 Program Clock Reference – Accuracy PCR_AC Definition The accuracy of the PCR values PCR_AC is defined as the difference between the actual PCR value and the value it should have in the TS represented by the byte index for its actual position. This can be calculated for constant bitrate TS, the measurement may NOT produce meaningful results in variable bitrate TS. The units for the parameter PCR_AC should be in nanoseconds. Purpose This measurement is designed to indicate the total error included in the PCR value with respect to its position in the TS. The tolerance as specified by ISO/IEC 13818-1 [i.1] is ±500 ns. This measurement is considered to be valid for both: real time and off-line measurements. The measurement should trigger the indicator under clause 5.2.2, item 2.4. Interface A. Z NOTE: Note that PCR Accuracy is defined by ISO/IEC 13818-1 [i.1]: "A tolerance is specified for the PCR values. The PCR tolerance is defined as the maximum inaccuracy allowed received PCRs. This inaccuracy may be due to imprecision in the PCR values or to PCR modification during re-multiplexing. It does not include errors in packet arrival time due to network jitter or other causes". |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.3 Bitrate measurement | |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.3.0 General | The bitrate value from a measurement system depends on a number of parameters: - when the bitrate measurement is started; - what is counted (packets, bytes, bits); - the time duration (gate) over which the bitrate is measured; - the way in which the time-gate function moves between measurements (timeSlice). |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.3.1 Bitrate measurement algorithm | This clause defines the parameter "MG bitrate" which is an instantaneous bitrate value. The bitrate is averaged over a fixed time gate (or "window"). This gating function is moved by a discrete time slice (or interval) to produce the bitrate value for each time slice. (The window "hops" from one time slice to the next) The items that are counted can be bits, bytes or Transport Stream packets, and the meaning of the measured value should be made clear by accurate labelling (see Nomenclature below). The measurement can be applied to the entire Transport Stream or a partial transport stream obtained by applying a PID filter or even a filter to remove packet headers. The following equation defines "MG bitrate": − = = − × Τ = 1 0 _ _ _ _ _ _ τ τ N n n n t t timeSlice in elements num e elementSiz timeSlice at bitrate MG Where: N is the integer number of time slices during the time gate. T = Nτ is the duration of the time gate in seconds. τ is the width of each time slice in seconds. element is the fundamental unit which is being counted by the bitrate measurement algorithm. elementSize is the size (measured in the appropriate units) of the element being measured. For example if bitrate units are packets/s then the elementSize should be expressed in packets. If bitrate units are bits/s then the elementSize is expressed in bits. Hence if an element is a 188 byte packets then elementSize can be expressed as: elementSize = 188 bytes/packet × 8 bits/byte = 1 504 bits ETSI ETSI TR 101 290 V1.4.1 (2020-06) 34 num_elements_in_timeSlice is the integer number of element starts which have occurred in the timeSlice. If an element is a 188 byte packet then this corresponds to counting sync bytes. If an element is a byte then this may correspond to counting the first bit in transmission order on a serial link. The units of MG_bitrate_at_timeSlicet are not part of the present document, but should be the same as the units used to express elementSize. This is because the bitrate can be expressed in a number of different ways as is described in the Nomenclature clause below. The measurement is discrete. A new measurement value is available every timeSlice and is held for the duration of a timeSlice. Display of a bitrate value in a piece of measurement equipment may not be a precise display of this value as is indicated in figure 5.4. measure Process for display Process for alarms Process for statistics etc … link to display Remote display Interface MGi1 Interface MGi2 Figure 5.4: Display of a bitrate value |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.3.2 Preferred values for Bitrate Measurement | The preferred values for the algorithm are application dependent. One set of values may be appropriate for monitoring and another may be appropriate for precise measurements. In order to have consistent measurements between different equipment vendors, the following profiles are defined. (Note that the timeSlice interval τ can be expressed as a time or as a frequency for precision). ETSI ETSI TR 101 290 V1.4.1 (2020-06) 35 Table 5.1a: Preferred profiles for bitrate measurements MG Profile Profile Description Stream Type/Rate τ N T=Nτ element MGB1 This Profile is best geared towards applications where the bitrate is constant or slowly varying. It is compatible with much equipment developed before the present document was created. All 1 s 1 1 s 188 byte packet MGB2 This Profile provides overall consistent rate calculations while providing reasonable accuracy for most monitoring and troubleshooting applications. It is intended for CBR measurements whereas rapidly varying bitrates are more appropriately measured with the MGB3 or MGB4 profiles. All 100 ms 10 1 s 188 byte packet MGB3 This Profile provides for tracking of small variations in the multiplex rate of each element. All 1/90 kHz 1 800 20 ms 188 byte packet MGB4 This Profile provides for a longer term average for rate calculation but with repeatability between two different measurements of the same data. All 1/90 kHz 9 × 104 1 s 188 byte packet MGB5 This Profile allows the user to tune bitrate calculations based on the parameters that are most appropriate for a particular transport stream. It is very important that when this is done, the nomenclature used to define the bitrate clearly shows that bitrates for components are not directly comparable with each other: TS@MGB1 video@MGB3 audio@MGB4 the_rest@188,1s,100s etc. This follows the nomenclature guide in the present document and shows that it is unlikely that the sum of the bitrates of the TS components will equal the overall transport stream rate. Complete or partial transport stream User Def. User Def. User Def. 188 byte packet Applications of the profiles are given in the informative annex J. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.3.3 Nomenclature | It is important to display bitrate values in a way which allows comparison. Correct nomenclature can indicate for example that correction factors need to be applied to convert from a 204 byte packet bitrate measurement to a 188 byte packet measurement. This recommendation is for the "MG-bitrate" nomenclature. If the "MG bitrate" algorithm has been used, then bitrates are of the form: <bitrate_value> <units>@ MGprofile or <bitrate_value> <units> @ MG<element>, <timeslice>, <time_gate> [,<filter>] For example if the full transport stream bitrate of a 204 byte packet system is to be measured, then it is important to know the size of the packet (i.e. the elementSize) and the size of the time window which was measured to ensure repeatability. Hence a bitrate should be expressed as: EXAMPLE 1: 10,300 Mbit/s @ MG 204,1/90 kHz, 1,1 s 1 It is assumed by default that the bitrate was for the full transport stream. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 36 If the bitrate of all the service components for a service called "Test Transmission" (i.e. all PIDs listed in the PMT + the bitrate of the PMT excluding the bitrate of EITp and EITf for that service) is to be measured, then it would be expressed as: EXAMPLE 2: 4,154 Mbit/s @ MG 188, 1/90 kHz, 1 s, service: Test Transmission or 4,154 Mbit/s @ MGB4, service: Test Transmission To express example 2 as a percentage of the total bitrate in example 1, it is obvious now that a 188/204 correction factor needs to be applied before the division takes place: Test Transmission = 100 × (4,154 × 204/188)/10,300 % of bitrate 43,8 % of bitrate Note that this nomenclature is independent of the measurement technique, but is vital to allow results to be compared. Note also that when writing MG-bitrate measurements, the values kbit/s and Mbit/s are taken to mean 103 bits per second and 106 bits per second respectively. It is also recommended that the values kB/s (103 bytes/s) and MB/s (106 bytes/s) are not used. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.4 Consistency of information check | |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.4.0 General | The information provided in the various SI/PSI tables in different Transport Streams needs to be consistent and coherent to provide access to all services for the user. Wherever these tables are created, modified or extracted, there is a need for checking the tables of the outgoing Transport Stream. In many cases, these applications are user-defined in the sense that providers and operators may wish to minimize the complexity of these checks. As a first example for such a check, the Transport_Stream_ID check is defined hereafter. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.4.1 Transport_Stream_ID check | Definition Each MPEG-2 Transport Stream should be identifiable by its Transport_Stream_ID carried in the PAT. Purpose As DVB networks become more and more complex, there is an increased risk of transmitting the wrong Transport Stream. Providers and operators may wish to make sure that the TS they actually process is the intended one. Interface A, Z Method The Transport Stream ID (as referenced in the PAT) should be checked and the actual TS ID should be compared with a user defined value. By this it can be tested whether the actual Transport Stream is the correct one. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.3.5 TS parameters in transmission systems with reduced SI data | Certain transmission systems, e.g. DSNG Transport Streams conforming to ETSI EN 301 210 [i.18] contain simplified PSI/SI information (see annex D of ETSI EN 301 210 [i.18]). When testing such Transport Streams, table 5.1b indicates which of the tests recommended in clause 5.2 can be used. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 37 Table 5.1b: TS parameters in systems with reduced SI data No. Indicator Comment 1.1 TS_sync_loss Essential for access to TS data 1.2 Sync_byte_error May not necessarily prevent decoding of content 1.3 PAT_error Essential for access to TS data 1.3.a PAT_error_2 Essential for access to TS data 1.4 Continuity_count_error May not necessarily prevent decoding of content 1.5 PMT_error Essential for access to TS data 1.5.a PMT_error_2 Essential for access to TS data 1.6 PID_error May not necessarily prevent decoding of content 2.1 Transport_error 2.2 CRC_error Applies to PAT and PMT only 2.3 PCR_error 2.3a PCR_repetition_error 2.3b PCR_discontinuity_indicator_error 2.4 PCR_accuracy_error 2.5 PTS_error 2.6 CAT_error 3.3 Buffer_error 3.4 Unreferenced_PID 3.4.a Unreferenced_PID 3.9 Empty_buffer_error 3.10 Data_delay_error 5.4 Measurement of availability at MPEG-2 Transport Stream level Definitions of error events The following definitions are used to establish criteria for System Availability, Link Availability, and System Error Performance (e.g. for coverage measurement purposes) for distribution networks such as satellite (DVB-S and DVB-DSNG), cable (DVB-C), terrestrial (DVB-T) and microwave systems (DVB-MS, DVB-MC and DVB-MT) as well as for contribution networks (DVB-PDH ETSI ETS 300 813 [i.19] and DVB-SDH ETSI ETS 300 814 [i.20]). These definitions may also be used to test the performance of TSs in IRDs via Common Interfaces. Table 5.2: Error Events 5.4.1 Severely Disturbed Period (SDP): A period of sync loss (as defined in clause 5.2.1 of the present document, parameter 1.1) or loss of signal. 5.4.2 Errored Block (EB): An MPEG-2 TS packet with one or more uncorrectable errors, which is indicated by the transport_error_indicator flag set. See clause 5.2.2. 5.4.3 Errored Time Interval (ETI): A given time interval with one or more EBs. 5.4.3.a Errored Second (ES): A specific case of the ETI where the given time interval is one second. 5.4.4 Severely Errored Time Interval (SETI): A given time interval which contains greater than a specified percentage of errored blocks, or at least one SDP or part thereof. This percentage will not be specified in the present document, but should be the subject of agreements between the network operators and the program providers. 5.4.4a Severely Errored Second (SES): A specific case of the SETI where the given time interval is one second. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 38 5.4.5 Unavailable Time UAT A start of a period of Unavailable Time can be defined as: • either the onset of N consecutive SES/SETI events; or • the onset of a rolling window of length T in which M SES/SETI events occur. These time intervals/seconds are considered to be part of the Unavailable Time. A end of period of Unavailable Time can be defined accordingly as • the onset of N consecutive non-SES/SETI events; or • the onset of a rolling window of length T in which no SES/SETI events occur. These time intervals/seconds are considered to be part of Available Time. The values N, M and T could differ for different types of service (video, audio, data, etc.). Note that these tests are only possible if Reed-Solomon encoding was used upstream with respect to the measurement point. 5.5 Evaluation of service performance by combination of TS related parameters Void. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.6 Parameters for CI related applications | |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.6.0 Introduction | The Common Interface (CI) is - in principle - a Transport Stream interface but it has particular properties which require additional tests. The parameters defined in this clause are intended to enable reproducible and comparable measurements on the CI. As in the previous clauses on Transport Stream related tests and measurements, it cannot be assumed that these tests provide a complete analysis. They are also designed as a 'health check', not as an overall compliance or conformance test. The following reference model pictures the interfaces and the functional blocks which are referred to in the definitions of the tests. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 39 Figure 5.5: CI Reference model |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.6.1 Latency | Table 5.3 Parameter Purpose Interface Method Latency To determine the impact of one CI module on latency (or average delay) An - Bn Measure arrival time of synch bytes of corresponding TS packets at both interfaces TS(204) inv. FEC TS(188) Gap Inserter Module 1 TS descrambled to Demux and Decoder (part of Demux) Host internal external Module 2 Module n A1 B1 A2 B2 An Bn Co Cn C1 C2 GAP Extractor Cn-1 Typical CI Module Bx Ax Gap Processor Bx Ax Bypass Input Sidecar ETSI ETSI TR 101 290 V1.4.1 (2020-06) 40 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.6.2 CI_module_delay_variation | Table 5.4 Parameter Purpose Interface Method Reference CI_module_delay_ variation To check compliance with CI spec, to limit additional PCR jitter and support decodability Ax - Bx Measure delay for all corresponding bytes of each TS packet between input Ax and output Bx and calculate peak delay variation for each TS packet EN 50221 [i.23], clause 5.4.2 NOTE: Ax and Bx are the input and output of any one CI Module. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.6.3 Input_output_TS comparison | Table 5.5 Parameter Purpose Interface Method Input-output TS comparison To ensure that modules under test do not impair other parts of the TS Co - Cn TS with at least 1 PID unaffected by the CI modules + other PIDs which will activate each module under test and carry out a bitwise comparison for the unaffected PIDs; additionally the CI modules should be tested while inactive |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.6.4 CI_module_throughput | Table 5.6 Parameter Purpose Interface Method Limits Period between consecutive synch bytes To ensure compliance with CI spec Ax, Bx or Cx Measure time between 2 synch bytes after processing in modules @ Ax: modules able to accept input TS @ Bx: module outputs TS within limits 58 Mbit/s from EN 50221 [i.23] NOTE: Ax and Bx are the input and output of any one CI Module, Cx is any corresponding interface of the host device. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 5.6.5 Valid TS on CI | Table 5.7 Parameter Purpose Interface Method Valid TS To ensure decodability Ax, Bx or Cx Checks as in Table 5.0a (1st priority) and 2.6 in Table 5.0b NOTE: Ax and Bx are the input and output of any one CI Module, Cx is any corresponding interface of the host device. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 41 6 Common parameters for satellite and cable transmission media |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.1 System availability | Purpose The system availability describes the long-term quality of the complete digital transmission system from MPEG-2 encoder to the measurement point. Interface Z Method The definition of System Availability is based on the list of performance parameters of table 5.2: Severely Disturbed Period (SDP) Errored Block (EB) Errored Time Interval ETI/Errored Second (ES) Severely Errored Time Interval SETI/Severely Errored Second (SES) Unavailable Time UAT The System Availability is defined as the ratio of (Total Time - Unavailable Time) to Total Time. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.2 Link availability | Purpose The link availability describes the long term quality of a specified link in a digital transmission chain. It could be used as a quality of service parameter in contracts between network operators and program providers. Interface X (Overload indicator of the Reed Solomon decoder). Method The definition of Link availability is based on following performance parameters: Uncorrectable Packet (UP) An MPEG-2 TS packet with an uncorrectable error, which is indicated by overload at the Reed-Solomon decoder. Uncorrectable Time Interval UTI/Uncorrectable Second (US) A given time interval with one or more UPs. The US is a specific case of the UTI where the given time interval is one second. Severely Uncorrectable Time Interval (SUTI)/Severely Uncorrectable Second (SUS): A given time interval which contains greater than a specified percentage of Uncorrectable Packets, or at least one SDP (see clause 5.4) or part thereof. NOTE: This percentage will not be specified in the present document, but should be the subject of agreements between the network operators and the service providers. The SUS is a specific case of the SUTI where the given time interval is one second. Link Unavailable Time LUAT A start of a period of Link Unavailable Time can be defined as: • either the onset of N consecutive SUS/SUTI events; or • the onset of a rolling window of length T in which M SUS/SUTI events occur. These time intervals/seconds are considered to be part of the Link Unavailable Time. A end of period of Link Unavailable Time can be defined accordingly as: • the onset of N consecutive non-SUS/SUTI events; or • the onset of a rolling window of length T in which no SUS/SUTI events occur. These time intervals/seconds are considered to be part of Link Available Time. The values N, M and T could differ for different types of service (video, audio, data, etc.). ETSI ETSI TR 101 290 V1.4.1 (2020-06) 42 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.3 BER before RS decoder | |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.3.0 Introduction | Purpose The Bit Error Rate (BER) is the primary parameter which describes the quality of the digital transmission link. Interface W Method The BER is defined as the ratio between erroneous bits and the total number of transmitted bits. Two alternative methods are available; one for "Out of Service" and a second for "In Service" use. In both cases, the measurement should only be done within the "link available time" as defined in clause 6.2. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.3.1 Out of service | The basic principle of this measurement is to generate within the channel encoder a known, fixed, repeating sequence of bits, essentially of a pseudo random nature. In order to do this the data entering the sync-inversion/randomization function is a continuous repetition of one fixed TS packet. This sequence is defined as the null TS packet in ISO/IEC 13818-1 [i.1] with all data bytes set to 0x00. i.e. the fixed packet is defined as the four byte sequence 0x47, 0x1F, 0xFF, 0x10, followed by 184 zero bytes (0 x 00). Ideally this would be available as an encoding system option (see clause A.2). |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.3.2 In service | The basic assumption made in this measurement method is that the RS check bytes are computed for each link in the transmission chain. Under normal operational circumstances, the RS decoder will correct all errors and produce an error-free TS packet. If there are severe error-bursts, the RS decoding algorithm may be overloaded, and be unable to correct the packet. In this case the transport_error_indicator bit should be set, no other bits in the packet should be changed, and the 16 RS check bytes should be recalculated accordingly before re-transmission on to another link. The BER measured at any point in the transmission chain is then the BER for that particular link only. The number of erroneous bits within a TS packet will be estimated by comparing the bit pattern of this TS packet before and after RS decoding. If the measured value of BER exceeds 10-3 then the measurement should be regarded as unreliable due to the limits of the RS decoding algorithm. Any TS packet that the RS decoder is unable to correct should cause the calculation to be restarted. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.4 Error events logging | Purpose Error events logging creates a permanent error log which can subsequently be used to locate possible sources of errors. It may be used as a measure of "system availability" (see clause 6.1 above). Interface Z Method Loss of sync, loss of signal, and reception of errored TS packets are logged. In case of sync or signal loss, the absolute time of loss should be recorded, along with either the duration of loss or the time of recovery from loss. A default time resolution of 1 second is strongly recommended for this measurement, but other time intervals may be appropriate depending on the application. In case of reception of EBs (see clause 6.1), the number of such events in each second should be logged, together with the PID and the total number of received packets of this PID within the resolution time. Logging of any other parameters (e.g. overloading of Reed-Solomon decoder, original_network_id, service_id) are optional. The error log should store the most recent 1 000 error events as a minimum. Provision should be made to access all of the error information in a form suitable for further data processing. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 43 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.5 Transmitter symbol clock jitter and accuracy | Purpose Inaccuracies of the symbol clock concerning absolute frequency, frequency drift and jitter may introduce intersymbol interference. Additionally, the accuracy of transmitted clock references like the Program Clock Reference (PCR) can be influenced. Therefore the degradation of signal quality due to symbol clock inaccuracies has to be negligible. Symbol clock jitter and accuracy can be degraded if the symbol clock is directly synthesized from an unstable TS data clock. For this reason, the measurement should be performed while the transmitter is driven by a TS to ensure a worst case measurement is obtained. Interface E Method For measurements the absolute frequency, frequency wander and timing jitter are of interest. A PLL circuit can be used for synchronization to the symbol clock and according to the loop bandwidth, timing jitter is suppressed and low frequency drift (wander) is still present at the output of the loop oscillator. Jitter can be measured with an oscilloscope by triggering with the extracted clock. Jitter is usually expressed as a peak-to-peak value in UI (Unit Interval) where one UI is equal to one clock cycle (Tsymbol). For measurements of the absolute frequency and frequency wander the output of the clock extractor can be used or the symbol clock can be measured directly using an appropriate frequency counter. NOTE: This measurement refers to the physical layer of TS interconnection. See clause 5.3.2 for PCR measurements. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.6 RF/IF signal power | Purpose Level measurement is needed to set up a network. Interface Any RF/IF interface, N, P. Method The signal power, or wanted power, is defined as the mean power of the selected signal as would be measured with a thermal power sensor. Care should be taken to limit the measurement to the bandwidth of the wanted signal. When using a spectrum analyser or a calibrated receiver, it should integrate the signal power within the nominal bandwidth of the signal (symbol rate x(1 + α)). |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.7 Noise power | Purpose Noise is a significant impairment in a transmission network. Interface N (out of service) or T (in service) Method The noise power (mean power), or unwanted power, is measured with a spectrum analyser (out of service) or an estimate is obtained from the IQ diagram (in service), see clause 6.9.9. The noise level is specified using either the occupied bandwidth of the signal, which is equal to the symbol rate x (1 + α). See annex G. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.8 Bit error count after RS | Purpose To measure whether the MPEG-2 TS is quasi error free. Interface Z Method The same principle as used for the "Out of service measurement" of the "BER before the Reed-Solomon decoder" described in clause 6.3.2, with the modification that the result is presented as an error count rather than a ratio. The receiver only has to compare the received TS packets with the Null packets as defined in clause A.2. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 44 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.9 IQ signal analysis | |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.9.1 Introduction | Assuming: - a constellation diagram of M symbol points; and - a measurement sample of N data points, where N is sufficiently larger than M to deliver the wanted measurement accuracy; and - the co-ordinates of each received data point j being Ij + δIj, Qj + δQj where I and Q are the co-ordinates of the ideal symbol point and δI and δQ are the offsets forming the error vector of the data point (see clause A.3). Figure 6.1: Relationship between the parameters describing different IQ distortions Modulation Error Ratio (MER) and the related Error Vector Magnitude (EVM) are calculated from all N data points without special pre-calculation for the data belonging to the M symbol points. With the aim of separating individual influences from the received data, for each point i of the M symbol points the mean distance di and the distribution σi can be calculated from those δIj, δQj belonging to the point i. From the M values {d1, d2, ... dM} the influences/parameters: - origin offset; - amplitude Imbalance (AI); and - quadrature Error (QE), can be extracted and removed from the di values, allowing to calculate the Residual Target Error (RTE) with the same algorithm as the System Target Error (STE) from {d1, d2, ... dM}. From the statistical distribution of the M clouds (denoted by σi in figure 6.2) parameters: - phase jitter; and - CW interferer, may be extracted. The remaining clouds (after elimination of the above two influences) are assumed to be due to Gaussian noise only and are the basis for calculation of the signal-to-noise ratio. The parameter may include - besides noise - also some other disturbing effects, like small non-coherent interferers or residual errors from the equalizer. From the SNR value the Carrier/Noise value can be estimated (see clause A.3). When using the interfaces E or G filtering of the signal before the interface should be considered. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 45 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.9.2 Modulation Error Ratio (MER) | Purpose To provide a single "figure of merit" analysis of the received signal. This figure is computed to include the total signal degradation likely to be present at the input of a commercial receiver's decision circuits and so give an indication of the ability of that receiver to correctly decode the signal. Interface E, G, S, T Method The carrier frequency and symbol timing are recovered, which removes frequency error and phase rotation. Origin offset (e.g. cause by residual carrier or DC offset), quadrature error and amplitude imbalance are not corrected. A time record of N received symbol co-ordinate pairs ( ) j j Q I ~ , ~ is captured. For each received symbol, a decision is made as to which symbol was transmitted. The ideal position of the chosen symbol (the centre of the decision box) is represented by the vector ( ) j j Q I , . The error vector ( ) j j Q I δ δ , is defined as the distance from this ideal position to the actual position of the received symbol. In other words, the received vector ( ) j j Q I ~ , ~ is the sum of the ideal vector ( ) j j Q I , and the error vector ( ) j j Q I δ δ , . The sum of the squares of the magnitudes of the ideal symbol vectors is divided by the sum of the squares of the magnitudes of the symbol error vectors. The result, expressed as a power ratio in dB, is defined as the Modulation Error Ratio (MER). ( ) ( ) dB Q I Q I MER N j j j N j j j + + × = = = 1 2 2 1 2 2 10 log 10 δ δ The definition of MER does not assume the use of an equalizer, however the measuring receiver may include a commercial quality equalizer to give more representative results when the signal at the measurement point has linear impairments. When an MER figure is quoted it should be stated whether an equalizer has been used. It should be reconsidered that MER is just one way of computing a "figure of merit" for a vector modulated signal. Another "figure of merit" calculation is Error Vector Magnitude (EVM) defined in annex C. It is also shown in annex C that MER and EVM are closely related and that one can generally be computed from the other. MER is the preferred first choice for various reasons itemized in annex C. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.9.3 System Target Error (STE) (void) | Figure 6.2: Definition of Target Error Vector (TEV) (void) |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.9.4 Carrier suppression | Purpose A residual carrier is an unwanted coherent CW signal added to the QAM signal. It may have been produced by DC offset voltages of the modulating I and/or Q signal or by crosstalk from the modulating carrier within the modulator. Interface E, G, S, T Method Search for systematic deviations of all constellation points and isolate the residual carrier. Calculate the Carrier Suppression (CS) from the formula: × = RC sig P P CS 10 log 10 where PRC is the power of the residual carrier and Psig is the power of the QAM signal (without residual carrier). ETSI ETSI TR 101 290 V1.4.1 (2020-06) 46 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.9.5 Amplitude Imbalance (AI) | Purpose To separate the QAM distortions resulting from AI of the I and Q signal from all other kind of distortions. Interface E, G, S, T Method Calculate the I and Q gain values vI and vQ from all points in a constellation diagram eliminating all other influences. Calculate AI from νI and νQ: . ) , max( and ) , min( % 100 1 2 1 1 2 Q I Q I v v v v v v with v v AI = = × − = ( ) ( ) ( ) ( ) ( ) ( ) i Q i I i N j j Q i M i i Q i i Q N j j I i M i i I i i I d d d Q N d Q d Q M I N d I d I M = + = + = = + = = = = = 6.9.3) clause in given as id of component - (Q 6.9.3) clause in given as id of component - (I 1 1 1 1 1 1 1 1 δ ν δ ν ETSI ETSI TR 101 290 V1.4.1 (2020-06) 47 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.9.6 Quadrature Error (QE) | Purpose The phases of the two carriers feeding the I and Q modulators have to be orthogonal. If their phase difference is not 90° a typical distortion of the constellation diagram results. The receiver usually aligns its reference phase in such a way that the 90° error (Δϕ) is equally spread between ϕ1 and ϕ2. I Q Decision Boundary Signal Point Decision Boundary Box 1 ϕ 2 ϕ 90°-QE Figure 6.3: Distortion of constellation diagram resulting from I/Q Quadrature Error (QE) Interface E, G, S, T Method Search for the constellation diagram error shown in figure 6.3 and calculate the absolute value of the phase difference Δϕ = |ϕ1 - ϕ2| after having eliminated all other influences and convert this into degrees. [ ]° − × ° = 2 1 180 ϕ ϕ π QE |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.9.7 Residual Target Error (RTE) | Void. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.9.8 Coherent interferer | Purpose Coherent interferers (not necessarily related to the main carrier) are usually measured with a spectrum analyser (out of service, and in some cases in service with narrow resolution bandwidth filter and video filter at interfaces N and P) or either of the following methods described below (in service). In a constellation diagram a sine-wave interferer will change the noisy clouds of each system point into a "donut" shape. From the statistical distribution of the clouds, the amplitude of the interferer can be calculated if it is above a certain limit. If the frequency of the interferer is of interest or more than one interferer is present, the Fourier transform method should to be used. Interface E, G, S, T Method Perform a Fourier transform of a time record of error vectors to produce a frequency spectrum of the interferers. Alternatively, calculate the RMS magnitude ai of the coherent interferer preferably from the statistical distribution of the 4 inner clouds computed from the measurement sample. Normalize ai to Srms and express the result in dB. i rms a S I C 10 log 20 / × = [dB] NOTE 1: In the present document, the term "coherent" is applied to signals that have a high degree of correlation with a time shifted version of itself. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 48 EXAMPLE 1: Continuous Waves (CW) or even single channel analogue video modulated carriers, these signals are coherent although they do not need to be related to the carrier of the digital channel under test. NOTE 2: Non-coherent is applied to signals with very low correlation to a time shifted version of themselves. EXAMPLE 2: Random noise or digitally modulated carriers, as well as the combined result of inter-modulation by many carriers. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.9.9 Phase Jitter (PJ) | Purpose The PJ of an oscillator is due to fluctuations of its phase or frequency. Using such an oscillator to modulate a digital signal results in a sampling uncertainty in the receiver, because the carrier regeneration cannot follow the phase fluctuations. The signal points are arranged along a curved line crossing the centre of each decision boundary box as shown in figure 6.4 the four "corner decision boundary boxes". Q I "Corner Decision Boundary Box" for calculation of the Phase Jitter Arc section through a Figure 6.4: Position of arc section in the constellation diagram to define the PJ (example: 64-QAM) Interface E, G, S, T ETSI ETSI TR 101 290 V1.4.1 (2020-06) 49 Method Phase Jitter (PJ) can be calculated theoretically using the following algorithm: For every received symbol: 1) Calculate the angle between the I-axis of the constellation and the vector to the received symbol ) ~ , ~ ( Q I : I Q ~ ~ arctan 1 = φ 2) Calculate the angle between the I-axis of the constellation and the vector to the corresponding ideal symbol ) , ( Q I : I Q arctan 2 = φ 3) Calculate the error angle: 2 1 φ φ φ − = E From these N error angles calculate the RMS phase jitter: = = − = N i N i E E i i N N PJ 1 2 1 2 2 1 1 φ φ However, the following method may be more practical. The first approximation of the "arc section" of a "corner decision boundary box" is a straight line parallel to the diagonal of the "decision boundary box". Additionally the curvature of the Phase Jitter (PJ) trace has to be taken into account when calculating the standard deviation of the PJ. The mean value of the PJ is calculated in degrees. ( ) × − × × ° = d M PJ PJ 1 2 arcsin 180 σ π where M = order of QAM and 2d = distance between two successive boundary lines. Within the argument of the arc sine function, the standard deviation of the PJ is referenced to the distance from the centre of the "corner decision boundary box" to the centre point of the QAM signal. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.9.10 Signal-to-Noise Ratio (SNR) | Purpose See 6.9.1 Interface S, T Method See 6.9.1, G.8, A.3 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 6.10 Interference | Purpose In a CATV network interference products can be caused by modulators and frequency converters. Interface N (out of service) or S, T (in service). Method Out of service interference products are measured with a spectrum analyser and in some cases in-service measurements can be done if a narrow resolution bandwidth filter and video filtering is used to lower the response of the instrument to the signal spectrum. If the frequency of the expected interference is known, the measurement can be made easily and quickly. In-service information of coherent interference can be derived from the constellation, clause 6.9.8. In some circumstances the residual carrier level can be measured with a spectrum analyser, by using a narrow resolution bandwidth filter and video filtering, at the interfaces H, J, N, P. The CS can be calculated as ten times the logarithm (base 10) of the ratio of the signal power measured as described in clause 6.6, to the measured remaining carrier power. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 50 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 7 Cable specific measurements | |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 7.0 Introduction | In SMATV networks that distribute the 1st satellite IF directly to subscribers, some parameters of this clause can be defined accordingly for QPSK modulated signals. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 7.1 Noise margin | Purpose To provide an indication of the reliability of the transmission channel. The noise margin measurement is a more useful measure of system operating margin than a direct BER measurement due to the steepness of the BER curve. Interface The reference interface for the noise injection is the RF interface (N). For practical implementation, other interfaces can be used, provided equivalence can be shown, for example P. Method The noise margin is computed by adding white Gaussian noise on the received signal. The noise margin will be the difference in dB between the carrier to noise ratio (C/N) of the received signal and the carrier to noise ratio for a BER of 10-4 (before RS decoding). |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 7.2 Estimated noise margin | Purpose To provide an indication of the reliability of the transmission channel without switching off the service. The noise margin measurement is a more useful measure of system operating margin than a direct BER measurement due to the steepness of the BER curve. Interface T Method The estimated noise margin is computed by simulating the addition of white Gaussian noise to the demodulated data and predicting the resulting BER by statistical methods. The noise margin will be the difference in dB between the estimated SNR of the received signal and the synthesized SNR which gives a predicted BER of 10-4 (before RS decoding). |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 7.3 Signal quality margin test | Void. Figure 7.1: Quality thresholds for single constellation in the I/Q plane (void) ETSI ETSI TR 101 290 V1.4.1 (2020-06) 51 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 7.4 Equivalent Noise Degradation (END) | Purpose END is a measure of the implementation loss caused by the network or the equipment where the reference is the ideal performance. Interface T (BER) and N or P or R (noise injection) Method The END is obtained from the difference in dB of the C/N or Eb/N0 ratio needed to reach a BER of 10-4 and the C/N or Eb/N0 ratio that would theoretically give a BER of 10-4, for a Gaussian channel. Figure 7.2: Measurement of equivalent noise degradation ETSI ETSI TR 101 290 V1.4.1 (2020-06) 52 Figure 7.2 gives a quantitative curve of the BER in DVB-C systems. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 7.5 BER vs. Eb/N0 | Purpose The BER vs. Eb/N0 measurement enables a graph to be drawn which shows the implementation loss of the system over a range of Bit Error Rates. The residual BER at high Eb/N0 values is an indicator of possible network problems. C/N measurements can be converted to Eb/N0 as shown m f BW N C N E s noise b × + = 10 0 log 10 [in dB] m is the number of bits per symbol (m = 6 for 64-QAM) and N is measured in the Nyquist bandwidth (symbol rate as indicated in clause 6.7). Interface T (BER) and N or P or R (noise injection) Method The BER vs. Eb/N0 curve will be measured using the RF and noise power measurements described above. The BER range of interest is 10-7 to 10-3. The Eb/N0 value is based on the gross bitrate (including RS error correction) and the net bitrate value of Eb/N0 can easily be calculated using the RS rate, using the following conversion factor for a RS (204, 188) code (see annex G). dB 35 , 0 188 204 log 10 10 + = × |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 7.6 Phase noise of RF carrier | Purpose Phase noise can be introduced at the transmitter side or by the receiver due to unstable local oscillators. Phase noise outside the loop bandwidth of the carrier recovery circuit leads to a circular smearing of the constellation points in the I/Q plane. This reduces the operating margin (noise margin) of the system and may directly increase the BER. Interface Any RF/IF interface, N, P Method Phase noise power density is normally expressed in dBc/Hz at a certain frequency offset from the carrier. Out of service phase noise will be measured with a spectrum- or modulation- analyser. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 7.7 Amplitude, phase and impulse response of the channel | Purpose Linear distortions, like amplitude and phase response errors and echoes, will be caused for instance by long lengths of cable and the cascading of a high number of amplifiers. The impulse response is important to localize the discrete reflections that may occur in cable networks. Interface S, T Method The impulse response of the transmission channel can be calculated (inverse Fourier transform) from the amplitude and phase response. The amplitude and phase response are defined as the RF-channel response. The amplitude response of the transmission channel can be derived from the equalizer tap coefficients or can be calculated directly from the "I" and "Q" samples, for example by using auto- and cross-correlation functions. |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 7.8 Out of band emissions | Purpose To prevent interference in other channels in the network the RF signal should comply with the spectrum mask specified for the network under test. Interface Transmitter output, J Method Spectrum analyser ETSI ETSI TR 101 290 V1.4.1 (2020-06) 53 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 8 Satellite specific measurements | |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 8.1 BER before Viterbi decoding | Purpose This measurement gives an indication of the transmission link performance. Due to typical error rates ranging from 7 × 10-2 to 10-5 the measurement can be done in a reasonable amount of time. Outside of this range the accuracy of the results may not be guaranteed. Interface The measurement should be done before the Viterbi decoder (Interface T of the receiver). Method The signal after Viterbi decoding in the measurement instrument is coded again using the same coding scheme as in the transmitter, in order to produce an estimate of the originally coded I and Q sequences. These sequences are compared at bit level with the sign-values of the signals that are available before Viterbi decoding. The BER for the I and Q paths should be made available separately. The measurement should be based on at least several hundred bit errors. For fast evaluation, in the case that the BER is lower than 10-4, it should be possible to stop the measurement after approximately 1 second. For accurate measurement of Eb/N0 at the quasi error free threshold, the measurement time and the presentation of the result should be such that an accuracy of three decimal place can be achieved. The quasi error free threshold corresponds to a BER before Viterbi decoding in the range 7 × 10-2 to 7 × 10-3,depending on the selected convolutional code rate; or a BER after Viterbi decoding of 2 × 10-4. Figure 8.1: BER measurement before Viterbi decoding |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 8.2 Receive BER vs. Eb/N0 | Purpose To verify overall clear sky link performance and link margin using a reference down link for acceptance tests. Interface After Viterbi decoding, V Method This is an out-of-service-measurement. The BER measurement should be based on the null packets inserted at the modulator as defined in clause A.1. To obtain the various values necessary for the curve BER over Eb/N0, white Gaussian noise is injected at the receiver site. In order to get accurate results it should be verified that the inserted noise level is at least 15 dB above the system noise. This can easily be observed on a spectrum analyser by switching the inserted noise on and off. Stable reception conditions are a precondition for accurate measurement results. The RS decoding should be deactivated, or bypassed to avoid excessively long measurement periods. The BER range of interest is 10-9 to 10-2. The measurement values are compared with the theoretical values. The value for the Equivalent Noise Degradation (END) at a BER of 10-4 can be derived from this information as well. For evaluation of Eb/N0 only the number of information bits (the net bitrate) should be taken into account. ETSI ETSI TR 101 290 V1.4.1 (2020-06) 54 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 8.3 IF spectrum | Purpose To prevent interference into other channels and to be compliant with the DVB specification the modulator output spectrum should be according with the one specified in ETSI EN 300 421 [i.5]. Interface H, input of the up-converter, typically 70 MHz or 140 MHz (Modulator output plus equipment for the connection to the up-converter input). Method Spectrum analyser and template for amplitude response, network analyser and template for group delay response, both as specified in ETSI EN 300 421 [i.5]. 9 Measurements specific for a terrestrial (DVB-T) system |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 9.0 Introduction | The intention of these guidelines is to provide a list of measurements useful in a DVB-T OFDM environment. The different options could be selected by the users of the system. Equipment manufacturers (both transmitters and receivers) as well as the operators, can choose those measurements that best fit their needs. A list of the applicability of the measurement parameters described in the present document to the DVB-T transmitter, receiver and network is given in table 9.1. The measurements 6.1 "System availability" and 6.2 "Link availability" are also valid for Terrestrial (not only for Cable and Satellite) and for any contribution link like SDH, PDH, etc. Table 9.1: DVB-T measurement parameters and their applicability Measurement parameter Transmitter Network Receiver 1) RF frequency measurements 1.1) RF frequency accuracy (Precision) X 1.2) RF channel width (Sampling Frequency Accuracy) X 1.3) Symbol Length measurement at RF (Guard Interval verification) X 2) Selectivity X 3) AFC capture range X 4) Phase noise of local oscillators (LO) X X 5) RF/IF signal power X X X 6) Noise power X 7) RF and IF spectrum X 8) Receiver sensitivity/dynamic range for a Gaussian channel X 9) Equivalent Noise Degradation (END) X X 9a) Equivalent Noise Floor (ENF) X 10) Linearity characterization (shoulder attenuation) X 11) Power efficiency X 12) Coherent interferer X X 13) BER vs. C/N ratio by variation of transmitter power X X 14) BER vs. C/N ratio by variation of Gaussian noise power X X 15) BER before Viterbi (inner) decoder X X X 16) BER before RS (outer) decoder X X X 17) BER after RS (outer) decoder X X 18) I/Q analysis 18.1) N/A 18.2) Modulation Error Ratio X X X 18.3) System Target Error X X 18.4) Carrier Suppression X X 18.5) Amplitude Imbalance X X 18.6) Quadrature Error X X 18.7) Phase Jitter X X 19) Overall signal delay X X 20) SFN synchronization 20.1) MIP_timing_error X 20.2) MIP_structure_error X ETSI ETSI TR 101 290 V1.4.1 (2020-06) 55 Measurement parameter Transmitter Network Receiver 20.3) MIP_presence_error X 20.4) MIP_pointer_error X 20.5) MIP_periodicity_error X 20.6) MIP_ts_rate_error X 21) System Error Performance X X X Figure 9.1: Block diagram of a DVB-T transmitter Figure 9.2: Block diagram of a DVB-T receiver ETSI ETSI TR 101 290 V1.4.1 (2020-06) 56 |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 9.1 RF frequency measurements | |
8db1a1fae619f4f804112b02d36a85ca | 101 290 | 9.1.0 General | The accuracy of some basic parameters of the OFDM modulation may be carried out at the RF layer of the DVB-T signal. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.